Initialization of Scrambling Sequence for Data in Multicast and Broadcast Services

ABSTRACT

A wireless device may receive, based on an RNTI associated with a multicast and broadcast services (MBS) session, a group common downlink control information (DCI) scheduling a transport block (TB) of the MBS session. Based on the RNTI being associated with the MBS session, the wireless device may determine a scrambling identity for a TB of the MBS session. The wireless device may receive the TB scrambled with a scrambling sequence initialized based on a value of the scrambling identity and a value of the RNTI.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/976,962, filed Oct. 31, 2022, which is a continuation ofInternational Application No. PCT/US2021/055949, filed Oct. 21, 2021,which claims the benefit of U.S. Provisional Application No. 63/094,854,filed Oct. 21, 2020, all of which are hereby incorporated by referencein their entireties.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1A and FIG. 1B illustrate example mobile communication networks inwhich embodiments of the present disclosure may be implemented.

FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user planeand control plane protocol stack.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack of FIG. 2A.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack of FIG. 2A.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

FIG. 5A and FIG. 5B respectively illustrate a mapping between logicalchannels, transport channels, and physical channels for the downlink anduplink.

FIG. 6 is an example diagram showing RRC state transitions of a UE.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier.

FIG. 10A illustrates three carrier aggregation configurations with twocomponent carriers.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups.

FIG. 11A illustrates an example of an SS/PBCH block structure andlocation.

FIG. 11B illustrates an example of CSI-RSs that are mapped in the timeand frequency domains.

FIG. 12A and FIG. 12B respectively illustrate examples of three downlinkand uplink beam management procedures.

FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-stepcontention-based random access procedure, a two-step contention-freerandom access procedure, and another two-step random access procedure.

FIG. 14A illustrates an example of CORESET configurations for abandwidth part.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing.

FIG. 15 illustrates an example of a wireless device in communicationwith a base station.

FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structuresfor uplink and downlink transmission.

FIG. 17A, FIG. 17B and FIG. 17C illustrate examples of MAC subheaders,according to some embodiments.

FIG. 18A illustrates an example of a DL MAC PDU, according to someembodiments.

FIG. 18B illustrates an example of an UL MAC PDU, according to someembodiments.

FIG. 19 illustrates example LCIDs for downlink, according to someembodiments.

FIG. 20 illustrates example LCIDs for uplink, according to someembodiments.

FIG. 21A and FIG. 21B illustrate examples of SCellactivation/deactivation MAC CE formats, according to some embodiments.

FIG. 22 illustrates an example of BWP activation/deactivation on aSCell, according to some embodiments.

FIG. 23A, FIG. 23B and FIG. 23C illustrate examples of configurationparameters of a MIB, according to some embodiments.

FIG. 24 illustrates an example of RRC configuration of a SIB1 message,according to some embodiments.

FIG. 25 illustrates an example of RRC configuration of a downlink BWP,according to some embodiments.

FIG. 26 illustrates an example of RRC configuration of a search space,according to some embodiments.

FIG. 27A and FIG. 27B illustrate examples of unicast, broadcast andmulticast transmission, according to some embodiments.

FIG. 28A and FIG. 28B illustrate examples of MBS resource allocations,according to some embodiments.

FIG. 29 illustrates an example of HARQ process management in a HARQentity, according to some embodiments.

FIG. 30 illustrates an example of HARQ retransmission, according to someembodiments.

FIG. 31A and FIG. 31B illustrate examples of multicast retransmission ofan MBS TB and unicast retransmission of an MBS TB, according to someembodiments.

FIG. 32 is a flowchart illustrating an example of HARQ retransmission ofan MBS TB, according to some embodiments.

FIG. 33 illustrates an example of HARQ process management, according tosome embodiments.

FIG. 34 illustrates an example of HARQ retransmission of an MBS TB,according to some embodiments.

FIG. 35 is a flowchart illustrating an example of HARQ retransmission ofan MBS TB, according to some embodiments.

FIG. 36 is a flowchart illustrating an example of HARQ retransmission ofan MBS TB, according to some embodiments.

DETAILED DESCRIPTION

In the present disclosure, various embodiments are presented as examplesof how the disclosed techniques may be implemented and/or how thedisclosed techniques may be practiced in environments and scenarios. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe scope. In fact, after reading the description, it will be apparentto one skilled in the relevant art how to implement alternativeembodiments. The present embodiments should not be limited by any of thedescribed exemplary embodiments. The embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. Limitations, features, and/or elements from the disclosedexample embodiments may be combined to create further embodiments withinthe scope of the disclosure. Any figures which highlight thefunctionality and advantages, are presented for example purposes only.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or only optionallyused in some embodiments.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). When this disclosure refers to a base stationcommunicating with a plurality of wireless devices, this disclosure mayrefer to a subset of the total wireless devices in a coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE or 5G release with a given capability and in a given sectorof the base station. The plurality of wireless devices in thisdisclosure may refer to a selected plurality of wireless devices, and/ora subset of total wireless devices in a coverage area which performaccording to disclosed methods, and/or the like. There may be aplurality of base stations or a plurality of wireless devices in acoverage area that may not comply with the disclosed methods, forexample, those wireless devices or base stations may perform based onolder releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed by one or more of the various embodiments. The terms“comprises” and “consists of”, as used herein, enumerate one or morecomponents of the element being described. The term “comprises” isinterchangeable with “includes” and does not exclude unenumeratedcomponents from being included in the element being described. Bycontrast, “consists of” provides a complete enumeration of the one ormore components of the element being described. The term “based on”, asused herein, should be interpreted as “based at least in part on” ratherthan, for example, “based solely on”. The term “and/or” as used hereinrepresents any possible combination of enumerated elements. For example,“A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A,B, and C.

If A and B are sets and every element of A is an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1},{cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayrefer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Many features presented are described as being optional through the useof “may” or the use of parentheses. For the sake of brevity andlegibility, the present disclosure does not explicitly recite each andevery permutation that may be obtained by choosing from the set ofoptional features. The present disclosure is to be interpreted asexplicitly disclosing all such permutations. For example, a systemdescribed as having three optional features may be embodied in sevenways, namely with just one of the three possible features, with any twoof the three possible features or with three of the three possiblefeatures.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (e.g.hardware with a biological element) or a combination thereof, which maybe behaviorally equivalent. For example, modules may be implemented as asoftware routine written in a computer language configured to beexecuted by a hardware machine (such as C, C++, Fortran, Java, Basic,Matlab or the like) or a modeling/simulation program such as Simulink,Stateflow, GNU Octave, or Lab VIEWMathScript. It may be possible toimplement modules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++ or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The mentioned technologies areoften used in combination to achieve the result of a functional module.

FIG. 1A illustrates an example of a mobile communication network 100 inwhich embodiments of the present disclosure may be implemented. Themobile communication network 100 may be, for example, a public landmobile network (PLMN) run by a network operator. As illustrated in FIG.1A, the mobile communication network 100 includes a core network (CN)102, a radio access network (RAN) 104, and a wireless device 106.

The CN 102 may provide the wireless device 106 with an interface to oneor more data networks (DNs), such as public DNs (e.g., the Internet),private DNs, and/or intra-operator DNs. As part of the interfacefunctionality, the CN 102 may set up end-to-end connections between thewireless device 106 and the one or more DNs, authenticate the wirelessdevice 106, and provide charging functionality.

The RAN 104 may connect the CN 102 to the wireless device 106 throughradio communications over an air interface. As part of the radiocommunications, the RAN 104 may provide scheduling, radio resourcemanagement, and retransmission protocols. The communication directionfrom the RAN 104 to the wireless device 106 over the air interface isknown as the downlink and the communication direction from the wirelessdevice 106 to the RAN 104 over the air interface is known as the uplink.Downlink transmissions may be separated from uplink transmissions usingfrequency division duplexing (FDD), time-division duplexing (TDD),and/or some combination of the two duplexing techniques.

The term wireless device may be used throughout this disclosure to referto and encompass any mobile device or fixed (non-mobile) device forwhich wireless communication is needed or usable. For example, awireless device may be a telephone, smart phone, tablet, computer,laptop, sensor, meter, wearable device, Internet of Things (IoT) device,vehicle road side unit (RSU), relay node, automobile, and/or anycombination thereof. The term wireless device encompasses otherterminology, including user equipment (UE), user terminal (UT), accessterminal (AT), mobile station, handset, wireless transmit and receiveunit (WTRU), and/or wireless communication device.

The RAN 104 may include one or more base stations (not shown). The termbase station may be used throughout this disclosure to refer to andencompass a Node B (associated with UMTS and/or 3G standards), anEvolved Node B (eNB, associated with E-UTRA and/or 4G standards), aremote radio head (RRH), a baseband processing unit coupled to one ormore RRHs, a repeater node or relay node used to extend the coveragearea of a donor node, a Next Generation Evolved Node B (ng-eNB), aGeneration Node B (gNB, associated with NR and/or 5G standards), anaccess point (AP, associated with, for example, WiFi or any othersuitable wireless communication standard), and/or any combinationthereof. A base station may comprise at least one gNB Central Unit(gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

A base station included in the RAN 104 may include one or more sets ofantennas for communicating with the wireless device 106 over the airinterface. For example, one or more of the base stations may includethree sets of antennas to respectively control three cells (or sectors).The size of a cell may be determined by a range at which a receiver(e.g., a base station receiver) can successfully receive thetransmissions from a transmitter (e.g., a wireless device transmitter)operating in the cell. Together, the cells of the base stations mayprovide radio coverage to the wireless device 106 over a wide geographicarea to support wireless device mobility.

In addition to three-sector sites, other implementations of basestations are possible. For example, one or more of the base stations inthe RAN 104 may be implemented as a sectored site with more or less thanthree sectors. One or more of the base stations in the RAN 104 may beimplemented as an access point, as a baseband processing unit coupled toseveral remote radio heads (RRHs), and/or as a repeater or relay nodeused to extend the coverage area of a donor node. A baseband processingunit coupled to RRHs may be part of a centralized or cloud RANarchitecture, where the baseband processing unit may be eithercentralized in a pool of baseband processing units or virtualized. Arepeater node may amplify and rebroadcast a radio signal received from adonor node. A relay node may perform the same/similar functions as arepeater node but may decode the radio signal received from the donornode to remove noise before amplifying and rebroadcasting the radiosignal.

The RAN 104 may be deployed as a homogenous network of macrocell basestations that have similar antenna patterns and similar high-leveltransmit powers. The RAN 104 may be deployed as a heterogeneous network.In heterogeneous networks, small cell base stations may be used toprovide small coverage areas, for example, coverage areas that overlapwith the comparatively larger coverage areas provided by macrocell basestations. The small coverage areas may be provided in areas with highdata traffic (or so-called “hotspots”) or in areas with weak macrocellcoverage. Examples of small cell base stations include, in order ofdecreasing coverage area, microcell base stations, picocell basestations, and femtocell base stations or home base stations.

The Third-Generation Partnership Project (3GPP) was formed in 1998 toprovide global standardization of specifications for mobilecommunication networks similar to the mobile communication network 100in FIG. 1A. To date, 3GPP has produced specifications for threegenerations of mobile networks: a third generation (3G) network known asUniversal Mobile Telecommunications System (UMTS), a fourth generation(4G) network known as Long-Term Evolution (LTE), and a fifth generation(5G) network known as 5G System (5GS). Embodiments of the presentdisclosure are described with reference to the RAN of a 3GPP 5G network,referred to as next-generation RAN (NG-RAN). Embodiments may beapplicable to RANs of other mobile communication networks, such as theRAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those offuture networks yet to be specified (e.g., a 3GPP 6G network). NG-RANimplements 5G radio access technology known as New Radio (NR) and may beprovisioned to implement 4G radio access technology or other radioaccess technologies, including non-3GPP radio access technologies.

FIG. 1B illustrates another example mobile communication network 150 inwhich embodiments of the present disclosure may be implemented. Mobilecommunication network 150 may be, for example, a PLMN run by a networkoperator. As illustrated in FIG. 1B, mobile communication network 150includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and156B (collectively UEs 156). These components may be implemented andoperate in the same or similar manner as corresponding componentsdescribed with respect to FIG. 1A.

The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs,such as public DNs (e.g., the Internet), private DNs, and/orintra-operator DNs. As part of the interface functionality, the 5G-CN152 may set up end-to-end connections between the UEs 156 and the one ormore DNs, authenticate the UEs 156, and provide charging functionality.Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 maybe a service-based architecture. This means that the architecture of thenodes making up the 5G-CN 152 may be defined as network functions thatoffer services via interfaces to other network functions. The networkfunctions of the 5G-CN 152 may be implemented in several ways, includingas network elements on dedicated or shared hardware, as softwareinstances running on dedicated or shared hardware, or as virtualizedfunctions instantiated on a platform (e.g., a cloud-based platform).

As illustrated in FIG. 1B, the 5G-CN 152 includes an Access and MobilityManagement Function (AMF) 158A and a User Plane Function (UPF) 158B,which are shown as one component AMF/UPF 158 in FIG. 1B for ease ofillustration. The UPF 158B may serve as a gateway between the NG-RAN 154and the one or more DNs. The UPF 158B may perform functions such aspacket routing and forwarding, packet inspection and user plane policyrule enforcement, traffic usage reporting, uplink classification tosupport routing of traffic flows to the one or more DNs, quality ofservice (QoS) handling for the user plane (e.g., packet filtering,gating, uplink/downlink rate enforcement, and uplink trafficverification), downlink packet buffering, and downlink data notificationtriggering. The UPF 158B may serve as an anchor point forintra-/inter-Radio Access Technology (RAT) mobility, an externalprotocol (or packet) data unit (PDU) session point of interconnect tothe one or more DNs, and/or a branching point to support a multi-homedPDU session. The UEs 156 may be configured to receive services through aPDU session, which is a logical connection between a UE and a DN.

The AMF 158A may perform functions such as Non-Access Stratum (NAS)signaling termination, NAS signaling security, Access Stratum (AS)security control, inter-CN node signaling for mobility between 3GPPaccess networks, idle mode UE reachability (e.g., control and executionof paging retransmission), registration area management, intra-systemand inter-system mobility support, access authentication, accessauthorization including checking of roaming rights, mobility managementcontrol (subscription and policies), network slicing support, and/orsession management function (SMF) selection. NAS may refer to thefunctionality operating between a CN and a UE, and AS may refer to thefunctionality operating between the UE and a RAN.

The 5G-CN 152 may include one or more additional network functions thatare not shown in FIG. 1B for the sake of clarity. For example, the 5G-CN152 may include one or more of a Session Management Function (SMF), anNR Repository Function (NRF), a Policy Control Function (PCF), a NetworkExposure Function (NEF), a Unified Data Management (UDM), an ApplicationFunction (AF), and/or an Authentication Server Function (AUSF).

The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radiocommunications over the air interface. The NG-RAN 154 may include one ormore gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160)and/or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B(collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be moregenerically referred to as base stations. The gNBs 160 and ng-eNBs 162may include one or more sets of antennas for communicating with the UEs156 over an air interface. For example, one or more of the gNBs 160and/or one or more of the ng-eNBs 162 may include three sets of antennasto respectively control three cells (or sectors). Together, the cells ofthe gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs156 over a wide geographic area to support UE mobility.

As shown in FIG. 1B, the gNBs 160 and/or the ng-eNBs 162 may beconnected to the 5G-CN 152 by means of an NG interface and to other basestations by an Xn interface. The NG and Xn interfaces may be establishedusing direct physical connections and/or indirect connections over anunderlying transport network, such as an internet protocol (IP)transport network. The gNBs 160 and/or the ng-eNBs 162 may be connectedto the UEs 156 by means of a Uu interface. For example, as illustratedin FIG. 1B, gNB 160A may be connected to the UE 156A by means of a Uuinterface. The NG, Xn, and Uu interfaces are associated with a protocolstack. The protocol stacks associated with the interfaces may be used bythe network elements in FIG. 1B to exchange data and signaling messagesand may include two planes: a user plane and a control plane. The userplane may handle data of interest to a user. The control plane mayhandle signaling messages of interest to the network elements.

The gNBs 160 and/or the ng-eNBs 162 may be connected to one or moreAMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means ofone or more NG interfaces. For example, the gNB 160A may be connected tothe UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U)interface. The NG-U interface may provide delivery (e.g., non-guaranteeddelivery) of user plane PDUs between the gNB 160A and the UPF 158B. ThegNB 160A may be connected to the AMF 158A by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide, for example, NGinterface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, andconfiguration transfer and/or warning message transmission.

The gNBs 160 may provide NR user plane and control plane protocolterminations towards the UEs 156 over the Uu interface. For example, thegNB 160A may provide NR user plane and control plane protocolterminations toward the UE 156A over a Uu interface associated with afirst protocol stack. The ng-eNBs 162 may provide Evolved UMTSTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the UEs 156 over a Uu interface, where E-UTRArefers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocolterminations towards the UE 156B over a Uu interface associated with asecond protocol stack.

The 5G-CN 152 was described as being configured to handle NR and 4Gradio accesses. It will be appreciated by one of ordinary skill in theart that it may be possible for NR to connect to a 4G core network in amode known as “non-standalone operation.” In non-standalone operation, a4G core network is used to provide (or at least support) control-planefunctionality (e.g., initial access, mobility, and paging). Althoughonly one AMF/UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may beconnected to multiple AMF/UPF nodes to provide redundancy and/or to loadshare across the multiple AMF/UPF nodes.

As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between thenetwork elements in FIG. 1B may be associated with a protocol stack thatthe network elements use to exchange data and signaling messages. Aprotocol stack may include two planes: a user plane and a control plane.The user plane may handle data of interest to a user, and the controlplane may handle signaling messages of interest to the network elements.

FIG. 2A and FIG. 2B respectively illustrate examples of NR user planeand NR control plane protocol stacks for the Uu interface that liesbetween a UE 210 and a gNB 220. The protocol stacks illustrated in FIG.2A and FIG. 2B may be the same or similar to those used for the Uuinterface between, for example, the UE 156A and the gNB 160A shown inFIG. 1B.

FIG. 2A illustrates a NR user plane protocol stack comprising fivelayers implemented in the UE 210 and the gNB 220. At the bottom of theprotocol stack, physical layers (PHYs) 211 and 221 may provide transportservices to the higher layers of the protocol stack and may correspondto layer 1 of the Open Systems Interconnection (OSI) model. The nextfour protocols above PHYs 211 and 221 comprise media access controllayers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223,packet data convergence protocol layers (PDCPs) 214 and 224, and servicedata application protocol layers (SDAPs) 215 and 225. Together, thesefour protocols may make up layer 2, or the data link layer, of the OSImodel.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack. Starting from the top ofFIG. 2A and FIG. 3 , the SDAPs 215 and 225 may perform QoS flowhandling. The UE 210 may receive services through a PDU session, whichmay be a logical connection between the UE 210 and a DN. The PDU sessionmay have one or more QoS flows. A UPF of a CN (e.g., the UPF 158B) maymap IP packets to the one or more QoS flows of the PDU session based onQoS requirements (e.g., in terms of delay, data rate, and/or errorrate). The SDAPs 215 and 225 may perform mapping/de-mapping between theone or more QoS flows and one or more data radio bearers. Themapping/de-mapping between the QoS flows and the data radio bearers maybe determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210may be informed of the mapping between the QoS flows and the data radiobearers through reflective mapping or control signaling received fromthe gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 maymark the downlink packets with a QoS flow indicator (QFI), which may beobserved by the SDAP 215 at the UE 210 to determine themapping/de-mapping between the QoS flows and the data radio bearers.

The PDCPs 214 and 224 may perform header compression/decompression toreduce the amount of data that needs to be transmitted over the airinterface, ciphering/deciphering to prevent unauthorized decoding ofdata transmitted over the air interface, and integrity protection (toensure control messages originate from intended sources. The PDCPs 214and 224 may perform retransmissions of undelivered packets, in-sequencedelivery and reordering of packets, and removal of packets received induplicate due to, for example, an intra-gNB handover. The PDCPs 214 and224 may perform packet duplication to improve the likelihood of thepacket being received and, at the receiver, remove any duplicatepackets. Packet duplication may be useful for services that require highreliability.

Although not shown in FIG. 3 , PDCPs 214 and 224 may performmapping/de-mapping between a split radio bearer and RLC channels in adual connectivity scenario. Dual connectivity is a technique that allowsa UE to connect to two cells or, more generally, two cell groups: amaster cell group (MCG) and a secondary cell group (SCG). A split beareris when a single radio bearer, such as one of the radio bearers providedby the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, ishandled by cell groups in dual connectivity. The PDCPs 214 and 224 maymap/de-map the split radio bearer between RLC channels belonging to cellgroups.

The RLCs 213 and 223 may perform segmentation, retransmission throughAutomatic Repeat Request (ARQ), and removal of duplicate data unitsreceived from MACs 212 and 222, respectively. The RLCs 213 and 223 maysupport three transmission modes: transparent mode (TM); unacknowledgedmode (UM); and acknowledged mode (AM). Based on the transmission mode anRLC is operating, the RLC may perform one or more of the notedfunctions. The RLC configuration may be per logical channel with nodependency on numerologies and/or Transmission Time Interval (TTI)durations. As shown in FIG. 3 , the RLCs 213 and 223 may provide RLCchannels as a service to PDCPs 214 and 224, respectively.

The MACs 212 and 222 may perform multiplexing/demultiplexing of logicalchannels and/or mapping between logical channels and transport channels.The multiplexing/demultiplexing may include multiplexing/demultiplexingof data units, belonging to the one or more logical channels, into/fromTransport Blocks (TBs) delivered to/from the PHYs 211 and 221. The MAC222 may be configured to perform scheduling, scheduling informationreporting, and priority handling between UEs by means of dynamicscheduling. Scheduling may be performed in the gNB 220 (at the MAC 222)for downlink and uplink. The MACs 212 and 222 may be configured toperform error correction through Hybrid Automatic Repeat Request (HARQ)(e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)),priority handling between logical channels of the UE 210 by means oflogical channel prioritization, and/or padding. The MACs 212 and 222 maysupport one or more numerologies and/or transmission timings. In anexample, mapping restrictions in a logical channel prioritization maycontrol which numerology and/or transmission timing a logical channelmay use. As shown in FIG. 3 , the MACs 212 and 222 may provide logicalchannels as a service to the RLCs 213 and 223.

The PHYs 211 and 221 may perform mapping of transport channels tophysical channels and digital and analog signal processing functions forsending and receiving information over the air interface. These digitaland analog signal processing functions may include, for example,coding/decoding and modulation/demodulation. The PHYs 211 and 221 mayperform multi-antenna mapping. As shown in FIG. 3 , the PHYs 211 and 221may provide one or more transport channels as a service to the MACs 212and 222.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack. FIG. 4A illustrates a downlink data flow of threeIP packets (n, n+1, and m) through the NR user plane protocol stack togenerate two TBs at the gNB 220. An uplink data flow through the NR userplane protocol stack may be similar to the downlink data flow depictedin FIG. 4A.

The downlink data flow of FIG. 4A begins when SDAP 225 receives thethree IP packets from one or more QoS flows and maps the three packetsto radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 toa first radio bearer 402 and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” in FIG. 4A) is added to an IPpacket. The data unit from/to a higher protocol layer is referred to asa service data unit (SDU) of the lower protocol layer and the data unitto/from a lower protocol layer is referred to as a protocol data unit(PDU) of the higher protocol layer. As shown in FIG. 4A, the data unitfrom the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is aPDU of the SDAP 225.

The remaining protocol layers in FIG. 4A may perform their associatedfunctionality (e.g., with respect to FIG. 3 ), add correspondingheaders, and forward their respective outputs to the next lower layer.For example, the PDCP 224 may perform IP-header compression andciphering and forward its output to the RLC 223. The RLC 223 mayoptionally perform segmentation (e.g., as shown for IP packet m in FIG.4A) and forward its output to the MAC 222. The MAC 222 may multiplex anumber of RLC PDUs and may attach a MAC subheader to an RLC PDU to forma transport block. In NR, the MAC subheaders may be distributed acrossthe MAC PDU, as illustrated in FIG. 4A. In LTE, the MAC subheaders maybe entirely located at the beginning of the MAC PDU. The NR MAC PDUstructure may reduce processing time and associated latency because theMAC PDU subheaders may be computed before the full MAC PDU is assembled.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.The MAC subheader includes: an SDU length field for indicating thelength (e.g., in bytes) of the MAC SDU to which the MAC subheadercorresponds; a logical channel identifier (LCID) field for identifyingthe logical channel from which the MAC SDU originated to aid in thedemultiplexing process; a flag (F) for indicating the size of the SDUlength field; and a reserved bit (R) field for future use.

FIG. 4B further illustrates MAC control elements (CEs) inserted into theMAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may beinserted at the beginning of a MAC PDU for downlink transmissions (asshown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions.MAC CEs may be used for in-band control signaling. Example MAC CEsinclude: scheduling-related MAC CEs, such as buffer status reports andpower headroom reports; activation/deactivation MAC CEs, such as thosefor activation/deactivation of PDCP duplication detection, channel stateinformation (CSI) reporting, sounding reference signal (SRS)transmission, and prior configured components; discontinuous reception(DRX) related MAC CEs; timing advance MAC CEs; and random access relatedMAC CEs. A MAC CE may be preceded by a MAC subheader with a similarformat as described for MAC SDUs and may be identified with a reservedvalue in the LCID field that indicates the type of control informationincluded in the MAC CE.

Before describing the NR control plane protocol stack, logical channels,transport channels, and physical channels are first described as well asa mapping between the channel types. One or more of the channels may beused to carry out functions associated with the NR control planeprotocol stack described later below.

FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, amapping between logical channels, transport channels, and physicalchannels. Information is passed through channels between the RLC, theMAC, and the PHY of the NR protocol stack. A logical channel may be usedbetween the RLC and the MAC and may be classified as a control channelthat carries control and configuration information in the NR controlplane or as a traffic channel that carries data in the NR user plane. Alogical channel may be classified as a dedicated logical channel that isdedicated to a specific UE or as a common logical channel that may beused by more than one UE. A logical channel may also be defined by thetype of information it carries. The set of logical channels defined byNR include, for example:

-   -   a paging control channel (PCCH) for carrying paging messages        used to page a UE whose location is not known to the network on        a cell level;    -   a broadcast control channel (BCCH) for carrying system        information messages in the form of a master information block        (MIB) and several system information blocks (SIBs), wherein the        system information messages may be used by the UEs to obtain        information about how a cell is configured and how to operate        within the cell;    -   a common control channel (CCCH) for carrying control messages        together with random access;    -   a dedicated control channel (DCCH) for carrying control messages        to/from a specific the UE to configure the UE; and    -   a dedicated traffic channel (DTCH) for carrying user data        to/from a specific the UE.

Transport channels are used between the MAC and PHY layers and may bedefined by how the information they carry is transmitted over the airinterface. The set of transport channels defined by NR include, forexample:

-   -   a paging channel (PCH) for carrying paging messages that        originated from the PCCH;    -   a broadcast channel (BCH) for carrying the MIB from the BCCH;    -   a downlink shared channel (DL-SCH) for carrying downlink data        and signaling messages, including the SIBs from the BCCH;    -   an uplink shared channel (UL-SCH) for carrying uplink data and        signaling messages; and    -   a random access channel (RACH) for allowing a UE to contact the        network without any prior scheduling.

The PHY may use physical channels to pass information between processinglevels of the PHY. A physical channel may have an associated set oftime-frequency resources for carrying the information of one or moretransport channels. The PHY may generate control information to supportthe low-level operation of the PHY and provide the control informationto the lower levels of the PHY via physical control channels, known asL1/L2 control channels. The set of physical channels and physicalcontrol channels defined by NR include, for example:

-   -   a physical broadcast channel (PBCH) for carrying the MIB from        the BCH;    -   a physical downlink shared channel (PDSCH) for carrying downlink        data and signaling messages from the DL-SCH, as well as paging        messages from the PCH;    -   a physical downlink control channel (PDCCH) for carrying        downlink control information (DCI), which may include downlink        scheduling commands, uplink scheduling grants, and uplink power        control commands;    -   a physical uplink shared channel (PUSCH) for carrying uplink        data and signaling messages from the UL-SCH and in some        instances uplink control information (UCI) as described below;    -   a physical uplink control channel (PUCCH) for carrying UCI,        which may include HARQ acknowledgments, channel quality        indicators (CQI), pre-coding matrix indicators (PMI), rank        indicators (RI), and scheduling requests (SR); and    -   a physical random access channel (PRACH) for random access.

Similar to the physical control channels, the physical layer generatesphysical signals to support the low-level operation of the physicallayer. As shown in FIG. 5A and FIG. 5B, the physical layer signalsdefined by NR include: primary synchronization signals (PSS), secondarysynchronization signals (SSS), channel state information referencesignals (CSI-RS), demodulation reference signals (DMRS), soundingreference signals (SRS), and phase-tracking reference signals (PT-RS).These physical layer signals will be described in greater detail below.

FIG. 2B illustrates an example NR control plane protocol stack. As shownin FIG. 2B, the NR control plane protocol stack may use the same/similarfirst four protocol layers as the example NR user plane protocol stack.These four protocol layers include the PHYs 211 and 221, the MACs 212and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead ofhaving the SDAPs 215 and 225 at the top of the stack as in the NR userplane protocol stack, the NR control plane stack has radio resourcecontrols (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top ofthe NR control plane protocol stack.

The NAS protocols 217 and 237 may provide control plane functionalitybetween the UE 210 and the AMF 230 (e.g., the AMF 158A) or, moregenerally, between the UE 210 and the CN. The NAS protocols 217 and 237may provide control plane functionality between the UE 210 and the AMF230 via signaling messages, referred to as NAS messages. There is nodirect path between the UE 210 and the AMF 230 through which the NASmessages can be transported. The NAS messages may be transported usingthe AS of the Uu and NG interfaces. NAS protocols 217 and 237 mayprovide control plane functionality such as authentication, security,connection setup, mobility management, and session management.

The RRCs 216 and 226 may provide control plane functionality between theUE 210 and the gNB 220 or, more generally, between the UE 210 and theRAN. The RRCs 216 and 226 may provide control plane functionalitybetween the UE 210 and the gNB 220 via signaling messages, referred toas RRC messages. RRC messages may be transmitted between the UE 210 andthe RAN using signaling radio bearers and the same/similar PDCP, RLC,MAC, and PHY protocol layers. The MAC may multiplex control-plane anduser-plane data into the same transport block (TB). The RRCs 216 and 226may provide control plane functionality such as: broadcast of systeminformation related to AS and NAS; paging initiated by the CN or theRAN; establishment, maintenance and release of an RRC connection betweenthe UE 210 and the RAN; security functions including key management;establishment, configuration, maintenance and release of signaling radiobearers and data radio bearers; mobility functions; QoS managementfunctions; the UE measurement reporting and control of the reporting;detection of and recovery from radio link failure (RLF); and/or NASmessage transfer. As part of establishing an RRC connection, RRCs 216and 226 may establish an RRC context, which may involve configuringparameters for communication between the UE 210 and the RAN.

FIG. 6 is an example diagram showing RRC state transitions of a UE. TheUE may be the same or similar to the wireless device 106 depicted inFIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any otherwireless device described in the present disclosure. As illustrated inFIG. 6 , a UE may be in at least one of three RRC states: RRC connected602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRCinactive 606 (e.g., RRC_INACTIVE).

In RRC connected 602, the UE has an established RRC context and may haveat least one RRC connection with a base station. The base station may besimilar to one of the one or more base stations included in the RAN 104depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG.1B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other basestation described in the present disclosure. The base station with whichthe UE is connected may have the RRC context for the UE. The RRCcontext, referred to as the UE context, may comprise parameters forcommunication between the UE and the base station. These parameters mayinclude, for example: one or more AS contexts; one or more radio linkconfiguration parameters; bearer configuration information (e.g.,relating to a data radio bearer, signaling radio bearer, logicalchannel, QoS flow, and/or PDU session); security information; and/orPHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. Whilein RRC connected 602, mobility of the UE may be managed by the RAN(e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signallevels (e.g., reference signal levels) from a serving cell andneighboring cells and report these measurements to the base stationcurrently serving the UE. The UE's serving base station may request ahandover to a cell of one of the neighboring base stations based on thereported measurements. The RRC state may transition from RRC connected602 to RRC idle 604 through a connection release procedure 608 or to RRCinactive 606 through a connection inactivation procedure 610.

In RRC idle 604, an RRC context may not be established for the UE. InRRC idle 604, the UE may not have an RRC connection with the basestation. While in RRC idle 604, the UE may be in a sleep state for themajority of the time (e.g., to conserve battery power). The UE may wakeup periodically (e.g., once in every discontinuous reception cycle) tomonitor for paging messages from the RAN. Mobility of the UE may bemanaged by the UE through a procedure known as cell reselection. The RRCstate may transition from RRC idle 604 to RRC connected 602 through aconnection establishment procedure 612, which may involve a randomaccess procedure as discussed in greater detail below.

In RRC inactive 606, the RRC context previously established ismaintained in the UE and the base station. This allows for a fasttransition to RRC connected 602 with reduced signaling overhead ascompared to the transition from RRC idle 604 to RRC connected 602. Whilein RRC inactive 606, the UE may be in a sleep state and mobility of theUE may be managed by the UE through cell reselection. The RRC state maytransition from RRC inactive 606 to RRC connected 602 through aconnection resume procedure 614 or to RRC idle 604 though a connectionrelease procedure 616 that may be the same as or similar to connectionrelease procedure 608.

An RRC state may be associated with a mobility management mechanism. InRRC idle 604 and RRC inactive 606, mobility is managed by the UE throughcell reselection. The purpose of mobility management in RRC idle 604 andRRC inactive 606 is to allow the network to be able to notify the UE ofan event via a paging message without having to broadcast the pagingmessage over the entire mobile communications network. The mobilitymanagement mechanism used in RRC idle 604 and RRC inactive 606 may allowthe network to track the UE on a cell-group level so that the pagingmessage may be broadcast over the cells of the cell group that the UEcurrently resides within instead of the entire mobile communicationnetwork. The mobility management mechanisms for RRC idle 604 and RRCinactive 606 track the UE on a cell-group level. They may do so usingdifferent granularities of grouping. For example, there may be threelevels of cell-grouping granularity: individual cells; cells within aRAN area identified by a RAN area identifier (RAI); and cells within agroup of RAN areas, referred to as a tracking area and identified by atracking area identifier (TAI).

Tracking areas may be used to track the UE at the CN level. The CN(e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list ofTAIs associated with a UE registration area. If the UE moves, throughcell reselection, to a cell associated with a TAI not included in thelist of TAIs associated with the UE registration area, the UE mayperform a registration update with the CN to allow the CN to update theUE's location and provide the UE with a new the UE registration area.

RAN areas may be used to track the UE at the RAN level. For a UE in RRCinactive 606 state, the UE may be assigned a RAN notification area. ARAN notification area may comprise one or more cell identities, a listof RAIs, or a list of TAIs. In an example, a base station may belong toone or more RAN notification areas. In an example, a cell may belong toone or more RAN notification areas. If the UE moves, through cellreselection, to a cell not included in the RAN notification areaassigned to the UE, the UE may perform a notification area update withthe RAN to update the UE's RAN notification area.

A base station storing an RRC context for a UE or a last serving basestation of the UE may be referred to as an anchor base station. Ananchor base station may maintain an RRC context for the UE at leastduring a period of time that the UE stays in a RAN notification area ofthe anchor base station and/or during a period of time that the UE staysin RRC inactive 606.

A gNB, such as gNBs 160 in FIG. 1B, may be split in two parts: a centralunit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU maybe coupled to one or more gNB-DUs using an F1 interface. The gNB-CU maycomprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC,the MAC, and the PHY.

In NR, the physical signals and physical channels (discussed withrespect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequencydivisional multiplexing (OFDM) symbols. OFDM is a multicarriercommunication scheme that transmits data over F orthogonal subcarriers(or tones). Before transmission, the data may be mapped to a series ofcomplex symbols (e.g., M-quadrature amplitude modulation (M-QAM) orM-phase shift keying (M-PSK) symbols), referred to as source symbols,and divided into F parallel symbol streams. The F parallel symbolstreams may be treated as though they are in the frequency domain andused as inputs to an Inverse Fast Fourier Transform (IFFT) block thattransforms them into the time domain. The IFFT block may take in Fsource symbols at a time, one from each of the F parallel symbolstreams, and use each source symbol to modulate the amplitude and phaseof one of F sinusoidal basis functions that correspond to the Forthogonal subcarriers. The output of the IFFT block may be Ftime-domain samples that represent the summation of the F orthogonalsubcarriers. The F time-domain samples may form a single OFDM symbol.After some processing (e.g., addition of a cyclic prefix) andup-conversion, an OFDM symbol provided by the IFFT block may betransmitted over the air interface on a carrier frequency. The Fparallel symbol streams may be mixed using an FFT block before beingprocessed by the IFFT block. This operation produces Discrete FourierTransform (DFT)-precoded OFDM symbols and may be used by UEs in theuplink to reduce the peak to average power ratio (PAPR). Inverseprocessing may be performed on the OFDM symbol at a receiver using anFFT block to recover the data mapped to the source symbols.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped. An NR frame may be identified by a systemframe number (SFN). The SFN may repeat with a period of 1024 frames. Asillustrated, one NR frame may be 10 milliseconds (ms) in duration andmay include 10 subframes that are 1 ms in duration. A subframe may bedivided into slots that include, for example, 14 OFDM symbols per slot.

The duration of a slot may depend on the numerology used for the OFDMsymbols of the slot. In NR, a flexible numerology is supported toaccommodate different cell deployments (e.g., cells with carrierfrequencies below 1 GHz up to cells with carrier frequencies in themm-wave range). A numerology may be defined in terms of subcarrierspacing and cyclic prefix duration. For a numerology in NR, subcarrierspacings may be scaled up by powers of two from a baseline subcarrierspacing of 15 kHz, and cyclic prefix durations may be scaled down bypowers of two from a baseline cyclic prefix duration of 4.7 μs. Forexample, NR defines numerologies with the following subcarrierspacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30 kHz/2.3μs; 60 kHz/1.2 μs; 120 kHz/0.59 μs; and 240 kHz/0.29 μs.

A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols).A numerology with a higher subcarrier spacing has a shorter slotduration and, correspondingly, more slots per subframe. FIG. 7illustrates this numerology-dependent slot duration andslots-per-subframe transmission structure (the numerology with asubcarrier spacing of 240 kHz is not shown in FIG. 7 for ease ofillustration). A subframe in NR may be used as a numerology-independenttime reference, while a slot may be used as the unit upon which uplinkand downlink transmissions are scheduled. To support low latency,scheduling in NR may be decoupled from the slot duration and start atany OFDM symbol and last for as many symbols as needed for atransmission. These partial slot transmissions may be referred to asmini-slot or subslot transmissions.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier. The slot includes resource elements(REs) and resource blocks (RBs). An RE is the smallest physical resourcein NR. An RE spans one OFDM symbol in the time domain by one subcarrierin the frequency domain as shown in FIG. 8 . An RB spans twelveconsecutive REs in the frequency domain as shown in FIG. 8 . An NRcarrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers.Such a limitation, if used, may limit the NR carrier to 50, 100, 200,and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz,respectively, where the 400 MHz bandwidth may be set based on a 400 MHzper carrier bandwidth limit.

FIG. 8 illustrates a single numerology being used across the entirebandwidth of the NR carrier. In other example configurations, multiplenumerologies may be supported on the same carrier.

NR may support wide carrier bandwidths (e.g., up to 400 MHz for asubcarrier spacing of 120 kHz). Not all UEs may be able to receive thefull carrier bandwidth (e.g., due to hardware limitations). Also,receiving the full carrier bandwidth may be prohibitive in terms of UEpower consumption. In an example, to reduce power consumption and/or forother purposes, a UE may adapt the size of the UE's receive bandwidthbased on the amount of traffic the UE is scheduled to receive. This isreferred to as bandwidth adaptation.

NR defines bandwidth parts (BWPs) to support UEs not capable ofreceiving the full carrier bandwidth and to support bandwidthadaptation. In an example, a BWP may be defined by a subset ofcontiguous RBs on a carrier. A UE may be configured (e.g., via RRClayer) with one or more downlink BWPs and one or more uplink BWPs perserving cell (e.g., up to four downlink BWPs and up to four uplink BWPsper serving cell). At a given time, one or more of the configured BWPsfor a serving cell may be active. These one or more BWPs may be referredto as active BWPs of the serving cell. When a serving cell is configuredwith a secondary uplink carrier, the serving cell may have one or morefirst active BWPs in the uplink carrier and one or more second activeBWPs in the secondary uplink carrier.

For unpaired spectra, a downlink BWP from a set of configured downlinkBWPs may be linked with an uplink BWP from a set of configured uplinkBWPs if a downlink BWP index of the downlink BWP and an uplink BWP indexof the uplink BWP are the same. For unpaired spectra, a UE may expectthat a center frequency for a downlink BWP is the same as a centerfrequency for an uplink BWP.

For a downlink BWP in a set of configured downlink BWPs on a primarycell (PCell), a base station may configure a UE with one or more controlresource sets (CORESETs) for at least one search space. A search spaceis a set of locations in the time and frequency domains where the UE mayfind control information. The search space may be a UE-specific searchspace or a common search space (potentially usable by a plurality ofUEs). For example, a base station may configure a UE with a commonsearch space, on a PCell or on a primary secondary cell (PSCell), in anactive downlink BWP.

For an uplink BWP in a set of configured uplink BWPs, a BS may configurea UE with one or more resource sets for one or more PUCCH transmissions.A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in adownlink BWP according to a configured numerology (e.g., subcarrierspacing and cyclic prefix duration) for the downlink BWP. The UE maytransmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWPaccording to a configured numerology (e.g., subcarrier spacing andcyclic prefix length for the uplink BWP).

One or more BWP indicator fields may be provided in Downlink ControlInformation (DCI). A value of a BWP indicator field may indicate whichBWP in a set of configured BWPs is an active downlink BWP for one ormore downlink receptions. The value of the one or more BWP indicatorfields may indicate an active uplink BWP for one or more uplinktransmissions.

A base station may semi-statically configure a UE with a defaultdownlink BWP within a set of configured downlink BWPs associated with aPCell. If the base station does not provide the default downlink BWP tothe UE, the default downlink BWP may be an initial active downlink BWP.The UE may determine which BWP is the initial active downlink BWP basedon a CORESET configuration obtained using the PBCH.

A base station may configure a UE with a BWP inactivity timer value fora PCell. The UE may start or restart a BWP inactivity timer at anyappropriate time. For example, the UE may start or restart the BWPinactivity timer (a) when the UE detects a DCI indicating an activedownlink BWP other than a default downlink BWP for a paired spectraoperation; or (b) when a UE detects a DCI indicating an active downlinkBWP or active uplink BWP other than a default downlink BWP or uplink BWPfor an unpaired spectra operation. If the UE does not detect DCI duringan interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWPinactivity timer toward expiration (for example, increment from zero tothe BWP inactivity timer value, or decrement from the BWP inactivitytimer value to zero). When the BWP inactivity timer expires, the UE mayswitch from the active downlink BWP to the default downlink BWP.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of the BWP inactivitytimer (e.g., if the second BWP is the default BWP).

Downlink and uplink BWP switching (where BWP switching refers toswitching from a currently active BWP to a not currently active BWP) maybe performed independently in paired spectra. In unpaired spectra,downlink and uplink BWP switching may be performed simultaneously.Switching between configured BWPs may occur based on RRC signaling, DCI,expiration of a BWP inactivity timer, and/or an initiation of randomaccess.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier. A UE configured with the three BWPsmay switch from one BWP to another BWP at a switching point. In theexample illustrated in FIG. 9 , the BWPs include: a BWP 902 with abandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with abandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902 may be an initial active BWP, and the BWP 904 may be a default BWP.The UE may switch between BWPs at switching points. In the example ofFIG. 9 , the UE may switch from the BWP 902 to the BWP 904 at aswitching point 908. The switching at the switching point 908 may occurfor any suitable reason, for example, in response to an expiry of a BWPinactivity timer (indicating switching to the default BWP) and/or inresponse to receiving a DCI indicating BWP 904 as the active BWP. The UEmay switch at a switching point 910 from active BWP 904 to BWP 906 inresponse receiving a DCI indicating BWP 906 as the active BWP. The UEmay switch at a switching point 912 from active BWP 906 to BWP 904 inresponse to an expiry of a BWP inactivity timer and/or in responsereceiving a DCI indicating BWP 904 as the active BWP. The UE may switchat a switching point 914 from active BWP 904 to BWP 902 in responsereceiving a DCI indicating BWP 902 as the active BWP.

If a UE is configured for a secondary cell with a default downlink BWPin a set of configured downlink BWPs and a timer value, UE proceduresfor switching BWPs on a secondary cell may be the same/similar as thoseon a primary cell. For example, the UE may use the timer value and thedefault downlink BWP for the secondary cell in the same/similar manneras the UE would use these values for a primary cell.

To provide for greater data rates, two or more carriers can beaggregated and simultaneously transmitted to/from the same UE usingcarrier aggregation (CA). The aggregated carriers in CA may be referredto as component carriers (CCs). When CA is used, there are a number ofserving cells for the UE, one for a CC. The CCs may have threeconfigurations in the frequency domain.

FIG. 10A illustrates the three CA configurations with two CCs. In theintraband, contiguous configuration 1002, the two CCs are aggregated inthe same frequency band (frequency band A) and are located directlyadjacent to each other within the frequency band. In the intraband,non-contiguous configuration 1004, the two CCs are aggregated in thesame frequency band (frequency band A) and are separated in thefrequency band by a gap. In the interband configuration 1006, the twoCCs are located in frequency bands (frequency band A and frequency bandB).

In an example, up to 32 CCs may be aggregated. The aggregated CCs mayhave the same or different bandwidths, subcarrier spacing, and/orduplexing schemes (TDD or FDD). A serving cell for a UE using CA mayhave a downlink CC. For FDD, one or more uplink CCs may be optionallyconfigured for a serving cell. The ability to aggregate more downlinkcarriers than uplink carriers may be useful, for example, when the UEhas more data traffic in the downlink than in the uplink.

When CA is used, one of the aggregated cells for a UE may be referred toas a primary cell (PCell). The PCell may be the serving cell that the UEinitially connects to at RRC connection establishment, reestablishment,and/or handover. The PCell may provide the UE with NAS mobilityinformation and the security input. UEs may have different PCells. Inthe downlink, the carrier corresponding to the PCell may be referred toas the downlink primary CC (DL PCC). In the uplink, the carriercorresponding to the PCell may be referred to as the uplink primary CC(UL PCC). The other aggregated cells for the UE may be referred to assecondary cells (SCells). In an example, the SCells may be configuredafter the PCell is configured for the UE. For example, an SCell may beconfigured through an RRC Connection Reconfiguration procedure. In thedownlink, the carrier corresponding to an SCell may be referred to as adownlink secondary CC (DL SCC). In the uplink, the carrier correspondingto the SCell may be referred to as the uplink secondary CC (UL SCC).

Configured SCells for a UE may be activated and deactivated based on,for example, traffic and channel conditions. Deactivation of an SCellmay mean that PDCCH and PDSCH reception on the SCell is stopped andPUSCH, SRS, and CQI transmissions on the SCell are stopped. ConfiguredSCells may be activated and deactivated using a MAC CE with respect toFIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit perSCell) to indicate which SCells (e.g., in a subset of configured SCells)for the UE are activated or deactivated. Configured SCells may bedeactivated in response to an expiration of an SCell deactivation timer(e.g., one SCell deactivation timer per SCell).

Downlink control information, such as scheduling assignments andscheduling grants, for a cell may be transmitted on the cellcorresponding to the assignments and grants, which is known asself-scheduling. The DCI for the cell may be transmitted on anothercell, which is known as cross-carrier scheduling. Uplink controlinformation (e.g., HARQ acknowledgments and channel state feedback, suchas CQI, PMI, and/or RI) for aggregated cells may be transmitted on thePUCCH of the PCell. For a larger number of aggregated downlink CCs, thePUCCH of the PCell may become overloaded. Cells may be divided intomultiple PUCCH groups.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCHgroup 1050 may include one or more downlink CCs, respectively. In theexample of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: aPCell 1011, an SCell 1012, and an SCell 1013. The PUCCH group 1050includes three downlink CCs in the present example: a PCell 1051, anSCell 1052, and an SCell 1053. One or more uplink CCs may be configuredas a PCell 1021, an SCell 1022, and an SCell 1023. One or more otheruplink CCs may be configured as a primary Scell (PSCell) 1061, an SCell1062, and an SCell 1063. Uplink control information (UCI) related to thedownlink CCs of the PUCCH group 1010, shown as UCI 1031, UCI 1032, andUCI 1033, may be transmitted in the uplink of the PCell 1021. Uplinkcontrol information (UCI) related to the downlink CCs of the PUCCH group1050, shown as UCI 1071, UCI 1072, and UCI 1073, may be transmitted inthe uplink of the PSCell 1061. In an example, if the aggregated cellsdepicted in FIG. 10B were not divided into the PUCCH group 1010 and thePUCCH group 1050, a single uplink PCell to transmit UCI relating to thedownlink CCs, and the PCell may become overloaded. By dividingtransmissions of UCI between the PCell 1021 and the PSCell 1061,overloading may be prevented.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned with a physical cell ID and a cell index. The physicalcell ID or the cell index may identify a downlink carrier and/or anuplink carrier of the cell, for example, depending on the context inwhich the physical cell ID is used. A physical cell ID may be determinedusing a synchronization signal transmitted on a downlink componentcarrier. A cell index may be determined using RRC messages. In thedisclosure, a physical cell ID may be referred to as a carrier ID, and acell index may be referred to as a carrier index. For example, when thedisclosure refers to a first physical cell ID for a first downlinkcarrier, the disclosure may mean the first physical cell ID is for acell comprising the first downlink carrier. The same/similar concept mayapply to, for example, a carrier activation. When the disclosureindicates that a first carrier is activated, the specification may meanthat a cell comprising the first carrier is activated.

In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In anexample, a HARQ entity may operate on a serving cell. A transport blockmay be generated per assignment/grant per serving cell. A transportblock and potential HARQ retransmissions of the transport block may bemapped to a serving cell.

In the downlink, a base station may transmit (e.g., unicast, multicast,and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g.,PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in FIG. 5A). In theuplink, the UE may transmit one or more RSs to the base station (e.g.,DMRS, PT-RS, and/or SRS, as shown in FIG. 5B). The PSS and the SSS maybe transmitted by the base station and used by the UE to synchronize theUE to the base station. The PSS and the SSS may be provided in asynchronization signal (SS)/physical broadcast channel (PBCH) block thatincludes the PSS, the SSS, and the PBCH. The base station mayperiodically transmit a burst of SS/PBCH blocks.

FIG. 11A illustrates an example of an SS/PBCH block's structure andlocation. A burst of SS/PBCH blocks may include one or more SS/PBCHblocks (e.g., 4 SS/PBCH blocks, as shown in FIG. 11A). Bursts may betransmitted periodically (e.g., every 2 frames or 20 ms). A burst may berestricted to a half-frame (e.g., a first half-frame having a durationof 5 ms). It will be understood that FIG. 11A is an example, and thatthese parameters (number of SS/PBCH blocks per burst, periodicity ofbursts, position of burst within the frame) may be configured based on,for example: a carrier frequency of a cell in which the SS/PBCH block istransmitted; a numerology or subcarrier spacing of the cell; aconfiguration by the network (e.g., using RRC signaling); or any othersuitable factor. In an example, the UE may assume a subcarrier spacingfor the SS/PBCH block based on the carrier frequency being monitored,unless the radio network configured the UE to assume a differentsubcarrier spacing.

The SS/PBCH block may span one or more OFDM symbols in the time domain(e.g., 4 OFDM symbols, as shown in the example of FIG. 11A) and may spanone or more subcarriers in the frequency domain (e.g., 240 contiguoussubcarriers). The PSS, the SSS, and the PBCH may have a common centerfrequency. The PSS may be transmitted first and may span, for example, 1OFDM symbol and 127 subcarriers. The SSS may be transmitted after thePSS (e.g., two symbols later) and may span 1 OFDM symbol and 127subcarriers. The PBCH may be transmitted after the PSS (e.g., across thenext 3 OFDM symbols) and may span 240 subcarriers.

The location of the SS/PBCH block in the time and frequency domains maynot be known to the UE (e.g., if the UE is searching for the cell). Tofind and select the cell, the UE may monitor a carrier for the PSS. Forexample, the UE may monitor a frequency location within the carrier. Ifthe PSS is not found after a certain duration (e.g., 20 ms), the UE maysearch for the PSS at a different frequency location within the carrier,as indicated by a synchronization raster. If the PSS is found at alocation in the time and frequency domains, the UE may determine, basedon a known structure of the SS/PBCH block, the locations of the SSS andthe PBCH, respectively. The SS/PBCH block may be a cell-defining SSblock (CD-SSB). In an example, a primary cell may be associated with aCD-SSB. The CD-SSB may be located on a synchronization raster. In anexample, a cell selection/search and/or reselection may be based on theCD-SSB.

The SS/PBCH block may be used by the UE to determine one or moreparameters of the cell. For example, the UE may determine a physicalcell identifier (PCI) of the cell based on the sequences of the PSS andthe SSS, respectively. The UE may determine a location of a frameboundary of the cell based on the location of the SS/PBCH block. Forexample, the SS/PBCH block may indicate that it has been transmitted inaccordance with a transmission pattern, wherein a SS/PBCH block in thetransmission pattern is a known distance from the frame boundary.

The PBCH may use a QPSK modulation and may use forward error correction(FEC). The FEC may use polar coding. One or more symbols spanned by thePBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCHmay include an indication of a current system frame number (SFN) of thecell and/or a SS/PBCH block timing index. These parameters mayfacilitate time synchronization of the UE to the base station. The PBCHmay include a master information block (MIB) used to provide the UE withone or more parameters. The MIB may be used by the UE to locateremaining minimum system information (RMSI) associated with the cell.The RMSI may include a System Information Block Type 1 (SIB1). The SIB1may contain information needed by the UE to access the cell. The UE mayuse one or more parameters of the MIB to monitor PDCCH, which may beused to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may bedecoded using parameters provided in the MIB. The PBCH may indicate anabsence of SIB1. Based on the PBCH indicating the absence of SIB1, theUE may be pointed to a frequency. The UE may search for an SS/PBCH blockat the frequency to which the UE is pointed.

The UE may assume that one or more SS/PBCH blocks transmitted with asame SS/PBCH block index are quasi co-located (QCLed) (e.g., having thesame/similar Doppler spread, Doppler shift, average gain, average delay,and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCHblock transmissions having different SS/PBCH block indices.

SS/PBCH blocks (e.g., those within a half-frame) may be transmitted inspatial directions (e.g., using different beams that span a coveragearea of the cell). In an example, a first SS/PBCH block may betransmitted in a first spatial direction using a first beam, and asecond SS/PBCH block may be transmitted in a second spatial directionusing a second beam.

In an example, within a frequency span of a carrier, a base station maytransmit a plurality of SS/PBCH blocks. In an example, a first PCI of afirst SS/PBCH block of the plurality of SS/PBCH blocks may be differentfrom a second PCI of a second SS/PBCH block of the plurality of SS/PBCHblocks. The PCIs of SS/PBCH blocks transmitted in different frequencylocations may be different or the same.

The CSI-RS may be transmitted by the base station and used by the UE toacquire channel state information (CSI). The base station may configurethe UE with one or more CSI-RSs for channel estimation or any othersuitable purpose. The base station may configure a UE with one or moreof the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs.The UE may estimate a downlink channel state and/or generate a CSIreport based on the measuring of the one or more downlink CSI-RSs. TheUE may provide the CSI report to the base station. The base station mayuse feedback provided by the UE (e.g., the estimated downlink channelstate) to perform link adaptation.

The base station may semi-statically configure the UE with one or moreCSI-RS resource sets. A CSI-RS resource may be associated with alocation in the time and frequency domains and a periodicity. The basestation may selectively activate and/or deactivate a CSI-RS resource.The base station may indicate to the UE that a CSI-RS resource in theCSI-RS resource set is activated and/or deactivated.

The base station may configure the UE to report CSI measurements. Thebase station may configure the UE to provide CSI reports periodically,aperiodically, or semi-persistently. For periodic CSI reporting, the UEmay be configured with a timing and/or periodicity of a plurality of CSIreports. For aperiodic CSI reporting, the base station may request a CSIreport. For example, the base station may command the UE to measure aconfigured CSI-RS resource and provide a CSI report relating to themeasurements. For semi-persistent CSI reporting, the base station mayconfigure the UE to transmit periodically, and selectively activate ordeactivate the periodic reporting. The base station may configure the UEwith a CSI-RS resource set and CSI reports using RRC signaling.

The CSI-RS configuration may comprise one or more parameters indicating,for example, up to 32 antenna ports. The UE may be configured to employthe same OFDM symbols for a downlink CSI-RS and a control resource set(CORESET) when the downlink CSI-RS and CORESET are spatially QCLed andresource elements associated with the downlink CSI-RS are outside of thephysical resource blocks (PRBs) configured for the CORESET. The UE maybe configured to employ the same OFDM symbols for downlink CSI-RS andSS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatiallyQCLed and resource elements associated with the downlink CSI-RS areoutside of PRBs configured for the SS/PBCH blocks.

Downlink DMRSs may be transmitted by a base station and used by a UE forchannel estimation. For example, the downlink DMRS may be used forcoherent demodulation of one or more downlink physical channels (e.g.,PDSCH). An NR network may support one or more variable and/orconfigurable DMRS patterns for data demodulation. At least one downlinkDMRS configuration may support a front-loaded DMRS pattern. Afront-loaded DMRS may be mapped over one or more OFDM symbols (e.g., oneor two adjacent OFDM symbols). A base station may semi-staticallyconfigure the UE with a number (e.g. a maximum number) of front-loadedDMRS symbols for PDSCH. A DMRS configuration may support one or moreDMRS ports. For example, for single user-MIMO, a DMRS configuration maysupport up to eight orthogonal downlink DMRS ports per UE. Formultiuser-MIMO, a DMRS configuration may support up to 4 orthogonaldownlink DMRS ports per UE. A radio network may support (e.g., at leastfor CP-OFDM) a common DMRS structure for downlink and uplink, wherein aDMRS location, a DMRS pattern, and/or a scrambling sequence may be thesame or different. The base station may transmit a downlink DMRS and acorresponding PDSCH using the same precoding matrix. The UE may use theone or more downlink DMRSs for coherent demodulation/channel estimationof the PDSCH.

In an example, a transmitter (e.g., a base station) may use a precodermatrices for a part of a transmission bandwidth. For example, thetransmitter may use a first precoder matrix for a first bandwidth and asecond precoder matrix for a second bandwidth. The first precoder matrixand the second precoder matrix may be different based on the firstbandwidth being different from the second bandwidth. The UE may assumethat a same precoding matrix is used across a set of PRBs. The set ofPRBs may be denoted as a precoding resource block group (PRG).

A PDSCH may comprise one or more layers. The UE may assume that at leastone symbol with DMRS is present on a layer of the one or more layers ofthe PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

Downlink PT-RS may be transmitted by a base station and used by a UE forphase-noise compensation. Whether a downlink PT-RS is present or not maydepend on an RRC configuration. The presence and/or pattern of thedownlink PT-RS may be configured on a UE-specific basis using acombination of RRC signaling and/or an association with one or moreparameters employed for other purposes (e.g., modulation and codingscheme (MCS)), which may be indicated by DCI. When configured, a dynamicpresence of a downlink PT-RS may be associated with one or more DCIparameters comprising at least MCS. An NR network may support aplurality of PT-RS densities defined in the time and/or frequencydomains. When present, a frequency domain density may be associated withat least one configuration of a scheduled bandwidth. The UE may assume asame precoding for a DMRS port and a PT-RS port. A number of PT-RS portsmay be fewer than a number of DMRS ports in a scheduled resource.Downlink PT-RS may be confined in the scheduled time/frequency durationfor the UE. Downlink PT-RS may be transmitted on symbols to facilitatephase tracking at the receiver.

The UE may transmit an uplink DMRS to a base station for channelestimation. For example, the base station may use the uplink DMRS forcoherent demodulation of one or more uplink physical channels. Forexample, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH.The uplink DM-RS may span a range of frequencies that is similar to arange of frequencies associated with the corresponding physical channel.The base station may configure the UE with one or more uplink DMRSconfigurations. At least one DMRS configuration may support afront-loaded DMRS pattern. The front-loaded DMRS may be mapped over oneor more OFDM symbols (e.g., one or two adjacent OFDM symbols). One ormore uplink DMRSs may be configured to transmit at one or more symbolsof a PUSCH and/or a PUCCH. The base station may semi-staticallyconfigure the UE with a number (e.g. maximum number) of front-loadedDMRS symbols for the PUSCH and/or the PUCCH, which the UE may use toschedule a single-symbol DMRS and/or a double-symbol DMRS. An NR networkmay support (e.g., for cyclic prefix orthogonal frequency divisionmultiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink,wherein a DMRS location, a DMRS pattern, and/or a scrambling sequencefor the DMRS may be the same or different.

A PUSCH may comprise one or more layers, and the UE may transmit atleast one symbol with DMRS present on a layer of the one or more layersof the PUSCH. In an example, a higher layer may configure up to threeDMRSs for the PUSCH.

Uplink PT-RS (which may be used by a base station for phase trackingand/or phase-noise compensation) may or may not be present depending onan RRC configuration of the UE. The presence and/or pattern of uplinkPT-RS may be configured on a UE-specific basis by a combination of RRCsignaling and/or one or more parameters employed for other purposes(e.g., Modulation and Coding Scheme (MCS)), which may be indicated byDCI. When configured, a dynamic presence of uplink PT-RS may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of uplink PT-RS densities definedin time/frequency domain. When present, a frequency domain density maybe associated with at least one configuration of a scheduled bandwidth.The UE may assume a same precoding for a DMRS port and a PT-RS port. Anumber of PT-RS ports may be fewer than a number of DMRS ports in ascheduled resource. For example, uplink PT-RS may be confined in thescheduled time/frequency duration for the UE.

SRS may be transmitted by a UE to a base station for channel stateestimation to support uplink channel dependent scheduling and/or linkadaptation. SRS transmitted by the UE may allow a base station toestimate an uplink channel state at one or more frequencies. A schedulerat the base station may employ the estimated uplink channel state toassign one or more resource blocks for an uplink PUSCH transmission fromthe UE. The base station may semi-statically configure the UE with oneor more SRS resource sets. For an SRS resource set, the base station mayconfigure the UE with one or more SRS resources. An SRS resource setapplicability may be configured by a higher layer (e.g., RRC) parameter.For example, when a higher layer parameter indicates beam management, anSRS resource in a SRS resource set of the one or more SRS resource sets(e.g., with the same/similar time domain behavior, periodic, aperiodic,and/or the like) may be transmitted at a time instant (e.g.,simultaneously). The UE may transmit one or more SRS resources in SRSresource sets. An NR network may support aperiodic, periodic and/orsemi-persistent SRS transmissions. The UE may transmit SRS resourcesbased on one or more trigger types, wherein the one or more triggertypes may comprise higher layer signaling (e.g., RRC) and/or one or moreDCI formats. In an example, at least one DCI format may be employed forthe UE to select at least one of one or more configured SRS resourcesets. An SRS trigger type 0 may refer to an SRS triggered based on ahigher layer signaling. An SRS trigger type 1 may refer to an SRStriggered based on one or more DCI formats. In an example, when PUSCHand SRS are transmitted in a same slot, the UE may be configured totransmit SRS after a transmission of a PUSCH and a corresponding uplinkDMRS.

The base station may semi-statically configure the UE with one or moreSRS configuration parameters indicating at least one of following: a SRSresource configuration identifier; a number of SRS ports; time domainbehavior of an SRS resource configuration (e.g., an indication ofperiodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/orsubframe level periodicity; offset for a periodic and/or an aperiodicSRS resource; a number of OFDM symbols in an SRS resource; a startingOFDM symbol of an SRS resource; an SRS bandwidth; a frequency hoppingbandwidth; a cyclic shift; and/or an SRS sequence ID.

An antenna port is defined such that the channel over which a symbol onthe antenna port is conveyed can be inferred from the channel over whichanother symbol on the same antenna port is conveyed. If a first symboland a second symbol are transmitted on the same antenna port, thereceiver may infer the channel (e.g., fading gain, multipath delay,and/or the like) for conveying the second symbol on the antenna port,from the channel for conveying the first symbol on the antenna port. Afirst antenna port and a second antenna port may be referred to as quasico-located (QCLed) if one or more large-scale properties of the channelover which a first symbol on the first antenna port is conveyed may beinferred from the channel over which a second symbol on a second antennaport is conveyed. The one or more large-scale properties may comprise atleast one of: a delay spread; a Doppler spread; a Doppler shift; anaverage gain; an average delay; and/or spatial Receiving (Rx)parameters.

Channels that use beamforming require beam management. Beam managementmay comprise beam measurement, beam selection, and beam indication. Abeam may be associated with one or more reference signals. For example,a beam may be identified by one or more beamformed reference signals.The UE may perform downlink beam measurement based on downlink referencesignals (e.g., a channel state information reference signal (CSI-RS))and generate a beam measurement report. The UE may perform the downlinkbeam measurement procedure after an RRC connection is set up with a basestation.

FIG. 11B illustrates an example of channel state information referencesignals (CSI-RSs) that are mapped in the time and frequency domains. Asquare shown in FIG. 11B may span a resource block (RB) within abandwidth of a cell. A base station may transmit one or more RRCmessages comprising CSI-RS resource configuration parameters indicatingone or more CSI-RSs. One or more of the following parameters may beconfigured by higher layer signaling (e.g., RRC and/or MAC signaling)for a CSI-RS resource configuration: a CSI-RS resource configurationidentity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symboland resource element (RE) locations in a subframe), a CSI-RS subframeconfiguration (e.g., subframe location, offset, and periodicity in aradio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, acode division multiplexing (CDM) type parameter, a frequency density, atransmission comb, quasi co-location (QCL) parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

The three beams illustrated in FIG. 11B may be configured for a UE in aUE-specific configuration. Three beams are illustrated in FIG. 11B (beam#1, beam #2, and beam #3), more or fewer beams may be configured. Beam#1 may be allocated with CSI-RS 1101 that may be transmitted in one ormore subcarriers in an RB of a first symbol. Beam #2 may be allocatedwith CSI-RS 1102 that may be transmitted in one or more subcarriers inan RB of a second symbol. Beam #3 may be allocated with CSI-RS 1103 thatmay be transmitted in one or more subcarriers in an RB of a thirdsymbol. By using frequency division multiplexing (FDM), a base stationmay use other subcarriers in a same RB (for example, those that are notused to transmit CSI-RS 1101) to transmit another CSI-RS associated witha beam for another UE. By using time domain multiplexing (TDM), beamsused for the UE may be configured such that beams for the UE use symbolsfrom beams of other UEs.

CSI-RSs such as those illustrated in FIG. 11B (e.g., CSI-RS 1101, 1102,1103) may be transmitted by the base station and used by the UE for oneor more measurements. For example, the UE may measure a reference signalreceived power (RSRP) of configured CSI-RS resources. The base stationmay configure the UE with a reporting configuration and the UE mayreport the RSRP measurements to a network (for example, via one or morebase stations) based on the reporting configuration. In an example, thebase station may determine, based on the reported measurement results,one or more transmission configuration indication (TCI) statescomprising a number of reference signals. In an example, the basestation may indicate one or more TCI states to the UE (e.g., via RRCsignaling, a MAC CE, and/or a DCI). The UE may receive a downlinktransmission with a receive (Rx) beam determined based on the one ormore TCI states. In an example, the UE may or may not have a capabilityof beam correspondence. If the UE has the capability of beamcorrespondence, the UE may determine a spatial domain filter of atransmit (Tx) beam based on a spatial domain filter of the correspondingRx beam. If the UE does not have the capability of beam correspondence,the UE may perform an uplink beam selection procedure to determine thespatial domain filter of the Tx beam. The UE may perform the uplink beamselection procedure based on one or more sounding reference signal (SRS)resources configured to the UE by the base station. The base station mayselect and indicate uplink beams for the UE based on measurements of theone or more SRS resources transmitted by the UE.

In a beam management procedure, a UE may assess (e.g., measure) achannel quality of one or more beam pair links, a beam pair linkcomprising a transmitting beam transmitted by a base station and areceiving beam received by the UE. Based on the assessment, the UE maytransmit a beam measurement report indicating one or more beam pairquality parameters comprising, e.g., one or more beam identifications(e.g., a beam index, a reference signal index, or the like), RSRP, aprecoding matrix indicator (PMI), a channel quality indicator (CQI),and/or a rank indicator (RI).

FIG. 12A illustrates examples of three downlink beam managementprocedures: P1, P2, and P3. Procedure P1 may enable a UE measurement ontransmit (Tx) beams of a transmission reception point (TRP) (or multipleTRPs), e.g., to support a selection of one or more base station Tx beamsand/or UE Rx beams (shown as ovals in the top row and bottom row,respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweepfor a set of beams (shown, in the top rows of P1 and P2, as ovalsrotated in a counter-clockwise direction indicated by the dashed arrow).Beamforming at a UE may comprise an Rx beam sweep for a set of beams(shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwisedirection indicated by the dashed arrow). Procedure P2 may be used toenable a UE measurement on Tx beams of a TRP (shown, in the top row ofP2, as ovals rotated in a counter-clockwise direction indicated by thedashed arrow). The UE and/or the base station may perform procedure P2using a smaller set of beams than is used in procedure P1, or usingnarrower beams than the beams used in procedure P1. This may be referredto as beam refinement. The UE may perform procedure P3 for Rx beamdetermination by using the same Tx beam at the base station and sweepingan Rx beam at the UE.

FIG. 12B illustrates examples of three uplink beam managementprocedures: U1, U2, and U3. Procedure U1 may be used to enable a basestation to perform a measurement on Tx beams of a UE, e.g., to support aselection of one or more UE Tx beams and/or base station Rx beams (shownas ovals in the top row and bottom row, respectively, of U1).Beamforming at the UE may include, e.g., a Tx beam sweep from a set ofbeams (shown in the bottom rows of U1 and U3 as ovals rotated in aclockwise direction indicated by the dashed arrow). Beamforming at thebase station may include, e.g., an Rx beam sweep from a set of beams(shown, in the top rows of U1 and U2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). Procedure U2may be used to enable the base station to adjust its Rx beam when the UEuses a fixed Tx beam. The UE and/or the base station may performprocedure U2 using a smaller set of beams than is used in procedure P1,or using narrower beams than the beams used in procedure P1. This may bereferred to as beam refinement The UE may perform procedure U3 to adjustits Tx beam when the base station uses a fixed Rx beam.

A UE may initiate a beam failure recovery (BFR) procedure based ondetecting a beam failure. The UE may transmit a BFR request (e.g., apreamble, a UCI, an SR, a MAC CE, and/or the like) based on theinitiating of the BFR procedure. The UE may detect the beam failurebased on a determination that a quality of beam pair link(s) of anassociated control channel is unsatisfactory (e.g., having an error ratehigher than an error rate threshold, a received signal power lower thana received signal power threshold, an expiration of a timer, and/or thelike).

The UE may measure a quality of a beam pair link using one or morereference signals (RSs) comprising one or more SS/PBCH blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DMRSs). A quality of the beam pair link may be based on one or more ofa block error rate (BLER), an RSRP value, a signal to interference plusnoise ratio (SINR) value, a reference signal received quality (RSRQ)value, and/or a CSI value measured on RS resources. The base station mayindicate that an RS resource is quasi co-located (QCLed) with one ormore DM-RSs of a channel (e.g., a control channel, a shared datachannel, and/or the like). The RS resource and the one or more DMRSs ofthe channel may be QCLed when the channel characteristics (e.g., Dopplershift, Doppler spread, average delay, delay spread, spatial Rxparameter, fading, and/or the like) from a transmission via the RSresource to the UE are similar or the same as the channelcharacteristics from a transmission via the channel to the UE.

A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE mayinitiate a random access procedure. A UE in an RRC_IDLE state and/or anRRC_INACTIVE state may initiate the random access procedure to request aconnection setup to a network. The UE may initiate the random accessprocedure from an RRC_CONNECTED state. The UE may initiate the randomaccess procedure to request uplink resources (e.g., for uplinktransmission of an SR when there is no PUCCH resource available) and/oracquire uplink timing (e.g., when uplink synchronization status isnon-synchronized). The UE may initiate the random access procedure torequest one or more system information blocks (SIBs) (e.g., other systeminformation such as SIB2, SIB3, and/or the like). The UE may initiatethe random access procedure for a beam failure recovery request. Anetwork may initiate a random access procedure for a handover and/or forestablishing time alignment for an SCell addition.

FIG. 13A illustrates a four-step contention-based random accessprocedure. Prior to initiation of the procedure, a base station maytransmit a configuration message 1310 to the UE. The procedureillustrated in FIG. 13A comprises transmission of four messages: a Msg 11311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 mayinclude and/or be referred to as a preamble (or a random accesspreamble). The Msg 2 1312 may include and/or be referred to as a randomaccess response (RAR).

The configuration message 1310 may be transmitted, for example, usingone or more RRC messages. The one or more RRC messages may indicate oneor more random access channel (RACH) parameters to the UE. The one ormore RACH parameters may comprise at least one of following: generalparameters for one or more random access procedures (e.g.,RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon);and/or dedicated parameters (e.g., RACH-configDedicated). The basestation may broadcast or multicast the one or more RRC messages to oneor more UEs. The one or more RRC messages may be UE-specific (e.g.,dedicated RRC messages transmitted to a UE in an RRC_CONNECTED stateand/or in an RRC_INACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and/or an uplinktransmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313.Based on the one or more RACH parameters, the UE may determine areception timing and a downlink channel for receiving the Msg 2 1312 andthe Msg 4 1314.

The one or more RACH parameters provided in the configuration message1310 may indicate one or more Physical RACH (PRACH) occasions availablefor transmission of the Msg 1 1311. The one or more PRACH occasions maybe predefined. The one or more RACH parameters may indicate one or moreavailable sets of one or more PRACH occasions (e.g., prach-ConfigIndex).The one or more RACH parameters may indicate an association between (a)one or more PRACH occasions and (b) one or more reference signals. Theone or more RACH parameters may indicate an association between (a) oneor more preambles and (b) one or more reference signals. The one or morereference signals may be SS/PBCH blocks and/or CSI-RSs. For example, theone or more RACH parameters may indicate a number of SS/PBCH blocksmapped to a PRACH occasion and/or a number of preambles mapped to aSS/PBCH blocks.

The one or more RACH parameters provided in the configuration message1310 may be used to determine an uplink transmit power of Msg 1 1311and/or Msg 3 1313. For example, the one or more RACH parameters mayindicate a reference power for a preamble transmission (e.g., a receivedtarget power and/or an initial power of the preamble transmission).There may be one or more power offsets indicated by the one or more RACHparameters. For example, the one or more RACH parameters may indicate: apower ramping step; a power offset between SSB and CSI-RS; a poweroffset between transmissions of the Msg 1 1311 and the Msg 3 1313;and/or a power offset value between preamble groups. The one or moreRACH parameters may indicate one or more thresholds based on which theUE may determine at least one reference signal (e.g., an SSB and/orCSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrierand/or a supplemental uplink (SUL) carrier).

The Msg 1 1311 may include one or more preamble transmissions (e.g., apreamble transmission and one or more preamble retransmissions). An RRCmessage may be used to configure one or more preamble groups (e.g.,group A and/or group B). A preamble group may comprise one or morepreambles. The UE may determine the preamble group based on a pathlossmeasurement and/or a size of the Msg 3 1313. The UE may measure an RSRPof one or more reference signals (e.g., SSBs and/or CSI-RSs) anddetermine at least one reference signal having an RSRP above an RSRPthreshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSI-RS). The UEmay select at least one preamble associated with the one or morereference signals and/or a selected preamble group, for example, if theassociation between the one or more preambles and the at least onereference signal is configured by an RRC message.

The UE may determine the preamble based on the one or more RACHparameters provided in the configuration message 1310. For example, theUE may determine the preamble based on a pathloss measurement, an RSRPmeasurement, and/or a size of the Msg 3 1313. As another example, theone or more RACH parameters may indicate: a preamble format; a maximumnumber of preamble transmissions; and/or one or more thresholds fordetermining one or more preamble groups (e.g., group A and group B). Abase station may use the one or more RACH parameters to configure the UEwith an association between one or more preambles and one or morereference signals (e.g., SSBs and/or CSI-RSs). If the association isconfigured, the UE may determine the preamble to include in Msg 1 1311based on the association. The Msg 1 1311 may be transmitted to the basestation via one or more PRACH occasions. The UE may use one or morereference signals (e.g., SSBs and/or CSI-RSs) for selection of thepreamble and for determining of the PRACH occasion. One or more RACHparameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) mayindicate an association between the PRACH occasions and the one or morereference signals.

The UE may perform a preamble retransmission if no response is receivedfollowing a preamble transmission. The UE may increase an uplinktransmit power for the preamble retransmission. The UE may select aninitial preamble transmit power based on a pathloss measurement and/or atarget received preamble power configured by the network. The UE maydetermine to retransmit a preamble and may ramp up the uplink transmitpower. The UE may receive one or more RACH parameters (e.g.,PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preambleretransmission. The ramping step may be an amount of incrementalincrease in uplink transmit power for a retransmission. The UE may rampup the uplink transmit power if the UE determines a reference signal(e.g., SSB and/or CSI-RS) that is the same as a previous preambletransmission. The UE may count a number of preamble transmissions and/orretransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE maydetermine that a random access procedure completed unsuccessfully, forexample, if the number of preamble transmissions exceeds a thresholdconfigured by the one or more RACH parameters (e.g., preambleTransMax).

The Msg 2 1312 received by the UE may include an RAR. In some scenarios,the Msg 2 1312 may include multiple RARs corresponding to multiple UEs.The Msg 2 1312 may be received after or in response to the transmittingof the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH andindicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 1 1311 was received by the base station.The Msg 2 1312 may include a time-alignment command that may be used bythe UE to adjust the UE's transmission timing, a scheduling grant fortransmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI).After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion thatthe UE uses to transmit the preamble. For example, the UE may start thetime window one or more symbols after a last symbol of the preamble(e.g., at a first PDCCH occasion from an end of a preambletransmission). The one or more symbols may be determined based on anumerology. The PDCCH may be in a common search space (e.g., aType1-PDCCH common search space) configured by an RRC message. The UEmay identify the RAR based on a Radio Network Temporary Identifier(RNTI). RNTIs may be used depending on one or more events initiating therandom access procedure. The UE may use random access RNTI (RA-RNTI).The RA-RNTI may be associated with PRACH occasions in which the UEtransmits a preamble. For example, the UE may determine the RA-RNTIbased on: an OFDM symbol index; a slot index; a frequency domain index;and/or a UL carrier indicator of the PRACH occasions. An example ofRA-RNTI may be as follows:

RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

where s_id may be an index of a first OFDM symbol of the PRACH occasion(e.g., 0≤s_id<14), t_id may be an index of a first slot of the PRACHoccasion in a system frame (e.g., 0≤t_id≤80), f_id may be an index ofthe PRACH occasion in the frequency domain (e.g., 0≤f_id≤8), andul_carrier_id may be a UL carrier used for a preamble transmission(e.g., 0 for an NUL carrier, and 1 for an SUL carrier).

The UE may transmit the Msg 3 1313 in response to a successful receptionof the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312).The Msg 3 1313 may be used for contention resolution in, for example,the contention-based random access procedure illustrated in FIG. 13A. Insome scenarios, a plurality of UEs may transmit a same preamble to abase station and the base station may provide an RAR that corresponds toa UE. Collisions may occur if the plurality of UEs interpret the RAR ascorresponding to themselves. Contention resolution (e.g., using the Msg3 1313 and the Msg 4 1314) may be used to increase the likelihood thatthe UE does not incorrectly use an identity of another the UE. Toperform contention resolution, the UE may include a device identifier inthe Msg 3 1313 (e.g., a C-RNTI if assigned, a TC RNTI included in theMsg 2 1312, and/or any other suitable identifier).

The Msg 4 1314 may be received after or in response to the transmittingof the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the basestation will address the UE on the PDCCH using the C-RNTI. If the UE'sunique C-RNTI is detected on the PDCCH, the random access procedure isdetermined to be successfully completed. If a TC-RNTI is included in theMsg 3 1313 (e.g., if the UE is in an RRC IDLE state or not otherwiseconnected to the base station), Msg 4 1314 will be received using aDL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decodedand a MAC PDU comprises the UE contention resolution identity MAC CEthat matches or otherwise corresponds with the CCCH SDU sent (e.g.,transmitted) in Msg 3 1313, the UE may determine that the contentionresolution is successful and/or the UE may determine that the randomaccess procedure is successfully completed.

The UE may be configured with a supplementary uplink (SUL) carrier and anormal uplink (NUL) carrier. An initial access (e.g., random accessprocedure) may be supported in an uplink carrier. For example, a basestation may configure the UE with two separate RACH configurations: onefor an SUL carrier and the other for an NUL carrier. For random accessin a cell configured with an SUL carrier, the network may indicate whichcarrier to use (NUL or SUL). The UE may determine the SUL carrier, forexample, if a measured quality of one or more reference signals is lowerthan a broadcast threshold. Uplink transmissions of the random accessprocedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on theselected carrier. The UE may switch an uplink carrier during the randomaccess procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) inone or more cases. For example, the UE may determine and/or switch anuplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on achannel clear assessment (e.g., a listen-before-talk).

FIG. 13B illustrates a two-step contention-free random access procedure.Similar to the four-step contention-based random access procedureillustrated in FIG. 13A, a base station may, prior to initiation of theprocedure, transmit a configuration message 1320 to the UE. Theconfiguration message 1320 may be analogous in some respects to theconfiguration message 1310. The procedure illustrated in FIG. 13Bcomprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322.The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects tothe Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively.As will be understood from FIGS. 13A and 13B, the contention-free randomaccess procedure may not include messages analogous to the Msg 3 1313and/or the Msg 4 1314.

The contention-free random access procedure illustrated in FIG. 13B maybe initiated for a beam failure recovery, other SI request, SCelladdition, and/or handover. For example, a base station may indicate orassign to the UE the preamble to be used for the Msg 1 1321. The UE mayreceive, from the base station via PDCCH and/or RRC, an indication of apreamble (e.g., ra-PreambleIndex).

After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of abeam failure recovery request, the base station may configure the UEwith a separate time window and/or a separate PDCCH in a search spaceindicated by an RRC message (e.g., recoverySearchSpaceId). The UE maymonitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) onthe search space. In the contention-free random access procedureillustrated in FIG. 13B, the UE may determine that a random accessprocedure successfully completes after or in response to transmission ofMsg 1 1321 and reception of a corresponding Msg 2 1322. The UE maydetermine that a random access procedure successfully completes, forexample, if a PDCCH transmission is addressed to a C-RNTI. The UE maydetermine that a random access procedure successfully completes, forexample, if the UE receives an RAR comprising a preamble identifiercorresponding to a preamble transmitted by the UE and/or the RARcomprises a MAC sub-PDU with the preamble identifier. The UE maydetermine the response as an indication of an acknowledgement for an SIrequest.

FIG. 13C illustrates another two-step random access procedure. Similarto the random access procedures illustrated in FIGS. 13A and 13B, a basestation may, prior to initiation of the procedure, transmit aconfiguration message 1330 to the UE. The configuration message 1330 maybe analogous in some respects to the configuration message 1310 and/orthe configuration message 1320. The procedure illustrated in FIG. 13Ccomprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A1331 may comprise one or more transmissions of a preamble 1341 and/orone or more transmissions of a transport block 1342. The transport block1342 may comprise contents that are similar and/or equivalent to thecontents of the Msg 3 1313 illustrated in FIG. 13A. The transport block1342 may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like).The UE may receive the Msg B 1332 after or in response to transmittingthe Msg A 1331. The Msg B 1332 may comprise contents that are similarand/or equivalent to the contents of the Msg 2 1312 (e.g., an RAR)illustrated in FIGS. 13A and 13B and/or the Msg 4 1314 illustrated inFIG. 13A.

The UE may initiate the two-step random access procedure in FIG. 13C forlicensed spectrum and/or unlicensed spectrum. The UE may determine,based on one or more factors, whether to initiate the two-step randomaccess procedure. The one or more factors may be: a radio accesstechnology in use (e.g., LTE, NR, and/or the like); whether the UE hasvalid TA or not; a cell size; the UE's RRC state; a type of spectrum(e.g., licensed vs. unlicensed); and/or any other suitable factors.

The UE may determine, based on two-step RACH parameters included in theconfiguration message 1330, a radio resource and/or an uplink transmitpower for the preamble 1341 and/or the transport block 1342 included inthe Msg A 1331. The RACH parameters may indicate a modulation and codingschemes (MCS), a time-frequency resource, and/or a power control for thepreamble 1341 and/or the transport block 1342. A time-frequency resourcefor transmission of the preamble 1341 (e.g., a PRACH) and atime-frequency resource for transmission of the transport block 1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACHparameters may enable the UE to determine a reception timing and adownlink channel for monitoring for and/or receiving Msg B 1332.

The transport block 1342 may comprise data (e.g., delay-sensitive data),an identifier of the UE, security information, and/or device information(e.g., an International Mobile Subscriber Identity (IMSI)). The basestation may transmit the Msg B 1332 as a response to the Msg A 1331. TheMsg B 1332 may comprise at least one of following: a preambleidentifier; a timing advance command; a power control command; an uplinkgrant (e.g., a radio resource assignment and/or an MCS); a UE identifierfor contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI).The UE may determine that the two-step random access procedure issuccessfully completed if: a preamble identifier in the Msg B 1332 ismatched to a preamble transmitted by the UE; and/or the identifier ofthe UE in Msg B 1332 is matched to the identifier of the UE in the Msg A1331 (e.g., the transport block 1342).

A UE and a base station may exchange control signaling. The controlsignaling may be referred to as L1/L2 control signaling and mayoriginate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g.,layer 2). The control signaling may comprise downlink control signalingtransmitted from the base station to the UE and/or uplink controlsignaling transmitted from the UE to the base station.

The downlink control signaling may comprise: a downlink schedulingassignment; an uplink scheduling grant indicating uplink radio resourcesand/or a transport format; a slot format information; a preemptionindication; a power control command; and/or any other suitablesignaling. The UE may receive the downlink control signaling in apayload transmitted by the base station on a physical downlink controlchannel (PDCCH). The payload transmitted on the PDCCH may be referred toas downlink control information (DCI). In some scenarios, the PDCCH maybe a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

A base station may attach one or more cyclic redundancy check (CRC)parity bits to a DCI in order to facilitate detection of transmissionerrors. When the DCI is intended for a UE (or a group of the UEs), thebase station may scramble the CRC parity bits with an identifier of theUE (or an identifier of the group of the UEs). Scrambling the CRC paritybits with the identifier may comprise Modulo-2 addition (or an exclusiveOR operation) of the identifier value and the CRC parity bits. Theidentifier may comprise a 16-bit value of a radio network temporaryidentifier (RNTI).

DCIs may be used for different purposes. A purpose may be indicated bythe type of RNTI used to scramble the CRC parity bits. For example, aDCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) mayindicate paging information and/or a system information changenotification. The P-RNTI may be predefined as “FFFE” in hexadecimal. ADCI having CRC parity bits scrambled with a system information RNTI(SI-RNTI) may indicate a broadcast transmission of the systeminformation. The SI-RNTI may be predefined as “FFFF” in hexadecimal. ADCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI)may indicate a random access response (RAR). A DCI having CRC paritybits scrambled with a cell RNTI (C-RNTI) may indicate a dynamicallyscheduled unicast transmission and/or a triggering of PDCCH-orderedrandom access. A DCI having CRC parity bits scrambled with a temporarycell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIsconfigured to the UE by a base station may comprise a ConfiguredScheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI(TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI),a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI(INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-PersistentCSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI(MCS-C-RNTI), and/or the like.

Depending on the purpose and/or content of a DCI, the base station maytransmit the DCIs with one or more DCI formats. For example, DCI format0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may bea fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1may be used for scheduling of PUSCH in a cell (e.g., with more DCIpayloads than DCI format 0_0). DCI format 1_0 may be used for schedulingof PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g.,with compact DCI payloads). DCI format 1_1 may be used for scheduling ofPDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCIformat 2_0 may be used for providing a slot format indication to a groupof UEs. DCI format 2_1 may be used for notifying a group of UEs of aphysical resource block and/or OFDM symbol where the UE may assume notransmission is intended to the UE. DCI format 2_2 may be used fortransmission of a transmit power control (TPC) command for PUCCH orPUSCH. DCI format 2_3 may be used for transmission of a group of TPCcommands for SRS transmissions by one or more UEs. DCI format(s) for newfunctions may be defined in future releases. DCI formats may havedifferent DCI sizes, or may share the same DCI size.

After scrambling a DCI with a RNTI, the base station may process the DCIwith channel coding (e.g., polar coding), rate matching, scramblingand/or QPSK modulation. A base station may map the coded and modulatedDCI on resource elements used and/or configured for a PDCCH. Based on apayload size of the DCI and/or a coverage of the base station, the basestation may transmit the DCI via a PDCCH occupying a number ofcontiguous control channel elements (CCEs). The number of the contiguousCCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/orany other suitable number. A CCE may comprise a number (e.g., 6) ofresource-element groups (REGs). A REG may comprise a resource block inan OFDM symbol. The mapping of the coded and modulated DCI on theresource elements may be based on mapping of CCEs and REGs (e.g.,CCE-to-REG mapping).

FIG. 14A illustrates an example of CORESET configurations for abandwidth part. The base station may transmit a DCI via a PDCCH on oneor more control resource sets (CORESETs). A CORESET may comprise atime-frequency resource in which the UE tries to decode a DCI using oneor more search spaces. The base station may configure a CORESET in thetime-frequency domain. In the example of FIG. 14A, a first CORESET 1401and a second CORESET 1402 occur at the first symbol in a slot. The firstCORESET 1401 overlaps with the second CORESET 1402 in the frequencydomain. A third CORESET 1403 occurs at a third symbol in the slot. Afourth CORESET 1404 occurs at the seventh symbol in the slot. CORESETsmay have a different number of resource blocks in frequency domain.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing. The CCE-to-REG mappingmay be an interleaved mapping (e.g., for the purpose of providingfrequency diversity) or a non-interleaved mapping (e.g., for thepurposes of facilitating interference coordination and/orfrequency-selective transmission of control channels). The base stationmay perform different or same CCE-to-REG mapping on different CORESETs.A CORESET may be associated with a CCE-to-REG mapping by RRCconfiguration. A CORESET may be configured with an antenna port quasico-location (QCL) parameter. The antenna port QCL parameter may indicateQCL information of a demodulation reference signal (DMRS) for PDCCHreception in the CORESET.

The base station may transmit, to the UE, RRC messages comprisingconfiguration parameters of one or more CORESETs and one or more searchspace sets. The configuration parameters may indicate an associationbetween a search space set and a CORESET. A search space set maycomprise a set of PDCCH candidates formed by CCEs at a given aggregationlevel. The configuration parameters may indicate: a number of PDCCHcandidates to be monitored per aggregation level; a PDCCH monitoringperiodicity and a PDCCH monitoring pattern; one or more DCI formats tobe monitored by the UE; and/or whether a search space set is a commonsearch space set or a UE-specific search space set. A set of CCEs in thecommon search space set may be predefined and known to the UE. A set ofCCEs in the UE-specific search space set may be configured based on theUE's identity (e.g., C-RNTI).

As shown in FIG. 14B, the UE may determine a time-frequency resource fora CORESET based on RRC messages. The UE may determine a CCE-to-REGmapping (e.g., interleaved or non-interleaved, and/or mappingparameters) for the CORESET based on configuration parameters of theCORESET. The UE may determine a number (e.g., at most 10) of searchspace sets configured on the CORESET based on the RRC messages. The UEmay monitor a set of PDCCH candidates according to configurationparameters of a search space set. The UE may monitor a set of PDCCHcandidates in one or more CORESETs for detecting one or more DCIs.Monitoring may comprise decoding one or more PDCCH candidates of the setof the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common search spaces, and/or number of PDCCH candidates inthe UE-specific search spaces) and possible (or configured) DCI formats.The decoding may be referred to as blind decoding. The UE may determinea DCI as valid for the UE, in response to CRC checking (e.g., scrambledbits for CRC parity bits of the DCI matching a RNTI value). The UE mayprocess information contained in the DCI (e.g., a scheduling assignment,an uplink grant, power control, a slot format indication, a downlinkpreemption, and/or the like).

The UE may transmit uplink control signaling (e.g., uplink controlinformation (UCI)) to a base station. The uplink control signaling maycomprise hybrid automatic repeat request (HARQ) acknowledgements forreceived DL-SCH transport blocks. The UE may transmit the HARQacknowledgements after receiving a DL-SCH transport block. Uplinkcontrol signaling may comprise channel state information (CSI)indicating channel quality of a physical downlink channel. The UE maytransmit the CSI to the base station. The base station, based on thereceived CSI, may determine transmission format parameters (e.g.,comprising multi-antenna and beamforming schemes) for a downlinktransmission. Uplink control signaling may comprise scheduling requests(SR). The UE may transmit an SR indicating that uplink data is availablefor transmission to the base station. The UE may transmit a UCI (e.g.,HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via aphysical uplink control channel (PUCCH) or a physical uplink sharedchannel (PUSCH). The UE may transmit the uplink control signaling via aPUCCH using one of several PUCCH formats.

There may be five PUCCH formats and the UE may determine a PUCCH formatbased on a size of the UCI (e.g., a number of uplink symbols of UCItransmission and a number of UCI bits). PUCCH format 0 may have a lengthof one or two OFDM symbols and may include two or fewer bits. The UE maytransmit UCI in a PUCCH resource using PUCCH format 0 if thetransmission is over one or two symbols and the number of HARQ-ACKinformation bits with positive or negative SR (HARQ-ACK/SR bits) is oneor two. PUCCH format 1 may occupy a number between four and fourteenOFDM symbols and may include two or fewer bits. The UE may use PUCCHformat 1 if the transmission is four or more symbols and the number ofHARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or twoOFDM symbols and may include more than two bits. The UE may use PUCCHformat 2 if the transmission is over one or two symbols and the numberof UCI bits is two or more. PUCCH format 3 may occupy a number betweenfour and fourteen OFDM symbols and may include more than two bits. TheUE may use PUCCH format 3 if the transmission is four or more symbols,the number of UCI bits is two or more and PUCCH resource does notinclude an orthogonal cover code. PUCCH format 4 may occupy a numberbetween four and fourteen OFDM symbols and may include more than twobits. The UE may use PUCCH format 4 if the transmission is four or moresymbols, the number of UCI bits is two or more and the PUCCH resourceincludes an orthogonal cover code.

The base station may transmit configuration parameters to the UE for aplurality of PUCCH resource sets using, for example, an RRC message. Theplurality of PUCCH resource sets (e.g., up to four sets) may beconfigured on an uplink BWP of a cell. A PUCCH resource set may beconfigured with a PUCCH resource set index, a plurality of PUCCHresources with a PUCCH resource being identified by a PUCCH resourceidentifier (e.g., pucch-Resourceid), and/or a number (e.g. a maximumnumber) of UCI information bits the UE may transmit using one of theplurality of PUCCH resources in the PUCCH resource set. When configuredwith a plurality of PUCCH resource sets, the UE may select one of theplurality of PUCCH resource sets based on a total bit length of the UCIinformation bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bitlength of UCI information bits is two or fewer, the UE may select afirst PUCCH resource set having a PUCCH resource set index equal to “0”.If the total bit length of UCI information bits is greater than two andless than or equal to a first configured value, the UE may select asecond PUCCH resource set having a PUCCH resource set index equal to“1”. If the total bit length of UCI information bits is greater than thefirst configured value and less than or equal to a second configuredvalue, the UE may select a third PUCCH resource set having a PUCCHresource set index equal to “2”. If the total bit length of UCIinformation bits is greater than the second configured value and lessthan or equal to a third value (e.g., 1406), the UE may select a fourthPUCCH resource set having a PUCCH resource set index equal to “3”.

After determining a PUCCH resource set from a plurality of PUCCHresource sets, the UE may determine a PUCCH resource from the PUCCHresource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE maydetermine the PUCCH resource based on a PUCCH resource indicator in aDCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. Athree-bit PUCCH resource indicator in the DCI may indicate one of eightPUCCH resources in the PUCCH resource set. Based on the PUCCH resourceindicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using aPUCCH resource indicated by the PUCCH resource indicator in the DCI.

FIG. 15 illustrates an example of a wireless device 1502 incommunication with a base station 1504 in accordance with embodiments ofthe present disclosure. The wireless device 1502 and base station 1504may be part of a mobile communication network, such as the mobilecommunication network 100 illustrated in FIG. 1A, the mobilecommunication network 150 illustrated in FIG. 1B, or any othercommunication network. Only one wireless device 1502 and one basestation 1504 are illustrated in FIG. 15 , but it will be understood thata mobile communication network may include more than one UE and/or morethan one base station, with the same or similar configuration as thoseshown in FIG. 15 .

The base station 1504 may connect the wireless device 1502 to a corenetwork (not shown) through radio communications over the air interface(or radio interface) 1506. The communication direction from the basestation 1504 to the wireless device 1502 over the air interface 1506 isknown as the downlink, and the communication direction from the wirelessdevice 1502 to the base station 1504 over the air interface is known asthe uplink. Downlink transmissions may be separated from uplinktransmissions using FDD, TDD, and/or some combination of the twoduplexing techniques.

In the downlink, data to be sent to the wireless device 1502 from thebase station 1504 may be provided to the processing system 1508 of thebase station 1504. The data may be provided to the processing system1508 by, for example, a core network. In the uplink, data to be sent tothe base station 1504 from the wireless device 1502 may be provided tothe processing system 1518 of the wireless device 1502. The processingsystem 1508 and the processing system 1518 may implement layer 3 andlayer 2 OSI functionality to process the data for transmission. Layer 2may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer,for example, with respect to FIG. 2A, FIG. 2B, FIG. 3 , and FIG. 4A.Layer 3 may include an RRC layer as with respect to FIG. 2B.

After being processed by processing system 1508, the data to be sent tothe wireless device 1502 may be provided to a transmission processingsystem 1510 of base station 1504. Similarly, after being processed bythe processing system 1518, the data to be sent to base station 1504 maybe provided to a transmission processing system 1520 of the wirelessdevice 1502. The transmission processing system 1510 and thetransmission processing system 1520 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For transmit processing, the PHY layermay perform, for example, forward error correction coding of transportchannels, interleaving, rate matching, mapping of transport channels tophysical channels, modulation of physical channel, multiple-inputmultiple-output (MIMO) or multi-antenna processing, and/or the like.

At the base station 1504, a reception processing system 1512 may receivethe uplink transmission from the wireless device 1502. At the wirelessdevice 1502, a reception processing system 1522 may receive the downlinktransmission from base station 1504. The reception processing system1512 and the reception processing system 1522 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For receive processing, the PHY layer mayperform, for example, error detection, forward error correctiondecoding, deinterleaving, demapping of transport channels to physicalchannels, demodulation of physical channels, MIMO or multi-antennaprocessing, and/or the like.

As shown in FIG. 15 , a wireless device 1502 and the base station 1504may include multiple antennas. The multiple antennas may be used toperform one or more MIMO or multi-antenna techniques, such as spatialmultiplexing (e.g., single-user MIMO or multi-user MIMO),transmit/receive diversity, and/or beamforming. In other examples, thewireless device 1502 and/or the base station 1504 may have a singleantenna.

The processing system 1508 and the processing system 1518 may beassociated with a memory 1514 and a memory 1524, respectively. Memory1514 and memory 1524 (e.g., one or more non-transitory computer readablemediums) may store computer program instructions or code that may beexecuted by the processing system 1508 and/or the processing system 1518to carry out one or more of the functionalities discussed in the presentapplication. Although not shown in FIG. 15 , the transmission processingsystem 1510, the transmission processing system 1520, the receptionprocessing system 1512, and/or the reception processing system 1522 maybe coupled to a memory (e.g., one or more non-transitory computerreadable mediums) storing computer program instructions or code that maybe executed to carry out one or more of their respectivefunctionalities.

The processing system 1508 and/or the processing system 1518 maycomprise one or more controllers and/or one or more processors. The oneor more controllers and/or one or more processors may comprise, forexample, a general-purpose processor, a digital signal processor (DSP),a microcontroller, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) and/or other programmable logicdevice, discrete gate and/or transistor logic, discrete hardwarecomponents, an on-board unit, or any combination thereof. The processingsystem 1508 and/or the processing system 1518 may perform at least oneof signal coding/processing, data processing, power control,input/output processing, and/or any other functionality that may enablethe wireless device 1502 and the base station 1504 to operate in awireless environment.

The processing system 1508 and/or the processing system 1518 may beconnected to one or more peripherals 1516 and one or more peripherals1526, respectively. The one or more peripherals 1516 and the one or moreperipherals 1526 may include software and/or hardware that providefeatures and/or functionalities, for example, a speaker, a microphone, akeypad, a display, a touchpad, a power source, a satellite transceiver,a universal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, anelectronic control unit (e.g., for a motor vehicle), and/or one or moresensors (e.g., an accelerometer, a gyroscope, a temperature sensor, aradar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, acamera, and/or the like). The processing system 1508 and/or theprocessing system 1518 may receive user input data from and/or provideuser output data to the one or more peripherals 1516 and/or the one ormore peripherals 1526. The processing system 1518 in the wireless device1502 may receive power from a power source and/or may be configured todistribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, forexample, a battery, a solar cell, a fuel cell, or any combinationthereof. The processing system 1508 and/or the processing system 1518may be connected to a GPS chipset 1517 and a GPS chipset 1527,respectively. The GPS chipset 1517 and the GPS chipset 1527 may beconfigured to provide geographic location information of the wirelessdevice 1502 and the base station 1504, respectively.

FIG. 16A illustrates an example structure for uplink transmission. Abaseband signal representing a physical uplink shared channel mayperform one or more functions. The one or more functions may comprise atleast one of: scrambling; modulation of scrambled bits to generatecomplex-valued symbols; mapping of the complex-valued modulation symbolsonto one or several transmission layers; transform precoding to generatecomplex-valued symbols; precoding of the complex-valued symbols; mappingof precoded complex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 16A. These functions are illustrated as examplesand it is anticipated that other mechanisms may be implemented invarious embodiments.

FIG. 16B illustrates an example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or a complex-valued Physical Random Access Channel(PRACH) baseband signal. Filtering may be employed prior totransmission.

FIG. 16C illustrates an example structure for downlink transmissions. Abaseband signal representing a physical downlink channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

FIG. 16D illustrates another example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued OFDM baseband signal for an antenna port.Filtering may be employed prior to transmission.

A wireless device may receive from a base station one or more messages(e.g. RRC messages) comprising configuration parameters of a pluralityof cells (e.g. primary cell, secondary cell). The wireless device maycommunicate with at least one base station (e.g. two or more basestations in dual-connectivity) via the plurality of cells. The one ormore messages (e.g. as a part of the configuration parameters) maycomprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers forconfiguring the wireless device. For example, the configurationparameters may comprise parameters for configuring physical and MAClayer channels, bearers, etc. For example, the configuration parametersmay comprise parameters indicating values of timers for physical, MAC,RLC, PCDP, SDAP, RRC layers, and/or communication channels.

A timer may begin running once it is started and continue running untilit is stopped or until it expires. A timer may be started if it is notrunning or restarted if it is running. A timer may be associated with avalue (e.g. the timer may be started or restarted from a value or may bestarted from zero and expire once it reaches the value). The duration ofa timer may not be updated until the timer is stopped or expires (e.g.,due to BWP switching). A timer may be used to measure a timeperiod/window for a process. When the specification refers to animplementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or moretimers. For example, it will be understood that one or more of themultiple ways to implement a timer may be used to measure a timeperiod/window for the procedure. For example, a random access responsewindow timer may be used for measuring a window of time for receiving arandom access response. In an example, instead of starting and expiry ofa random access response window timer, the time difference between twotime stamps may be used. When a timer is restarted, a process formeasurement of time window may be restarted. Other exampleimplementations may be provided to restart a measurement of a timewindow.

A base station may transmit one or more MAC PDUs to a wireless device.In an example, a MAC PDU may be a bit string that is byte aligned (e.g.,aligned to a multiple of eight bits) in length. In an example, bitstrings may be represented by tables in which the most significant bitis the leftmost bit of the first line of the table, and the leastsignificant bit is the rightmost bit on the last line of the table. Moregenerally, the bit string may be read from left to right and then in thereading order of the lines. In an example, the bit order of a parameterfield within a MAC PDU is represented with the first and mostsignificant bit in the leftmost bit and the last and least significantbit in the rightmost bit.

In an example, a MAC SDU may be a bit string that is byte aligned (e.g.,aligned to a multiple of eight bits) in length. In an example, a MAC SDUmay be included in a MAC PDU from the first bit onward. A MAC CE may bea bit string that is byte aligned (e.g., aligned to a multiple of eightbits) in length. A MAC subheader may be a bit string that is bytealigned (e.g., aligned to a multiple of eight bits) in length. In anexample, a MAC subheader may be placed immediately in front of acorresponding MAC SDU, MAC CE, or padding. A MAC entity may ignore avalue of reserved bits in a DL MAC PDU.

In an example, a MAC PDU may comprise one or more MAC subPDUs. A MACsubPDU of the one or more MAC subPDUs may comprise: a MAC subheader only(including padding); a MAC subheader and a MAC SDU; a MAC subheader anda MAC CE; a MAC subheader and padding, or a combination thereof. The MACSDU may be of variable size. A MAC subheader may correspond to a MACSDU, a MAC CE, or padding.

In an example, when a MAC subheader corresponds to a MAC SDU, avariable-sized MAC CE, or padding, the MAC subheader may comprise: an Rfield with a one bit length; an F field with a one-bit length; an LCIDfield with a multi-bit length; an L field with a multi-bit length, or acombination thereof.

FIG. 17A shows an example of a MAC subheader with an R field, an Ffield, an LCID field, and an L field. In the example MAC subheader ofFIG. 17A, the LCID field may be six bits in length, and the L field maybe eight bits in length. FIG. 17B shows example of a MAC subheader withan R field, a F field, an LCID field, and an L field. In the example MACsubheader shown in FIG. 17B, the LCID field may be six bits in length,and the L field may be sixteen bits in length. When a MAC subheadercorresponds to a fixed sized MAC CE or padding, the MAC subheader maycomprise: a R field with a two-bit length and an LCID field with amulti-bit length. FIG. 17C shows an example of a MAC subheader with an Rfield and an LCID field. In the example MAC subheader shown in FIG. 17C,the LCID field may be six bits in length, and the R field may be twobits in length.

FIG. 18A shows an example of a DL MAC PDU. Multiple MAC CEs, such as MACCE 1 and 2, may be placed together. A MAC subPDU, comprising a MAC CE,may be placed before: a MAC subPDU comprising a MAC SDU, or a MAC subPDUcomprising padding. FIG. 18B shows an example of a UL MAC PDU. MultipleMAC CEs, such as MAC CE 1 and 2, may be placed together. In anembodiment, a MAC subPDU comprising a MAC CE may be placed after all MACsubPDUs comprising a MAC SDU. In addition, the MAC subPDU may be placedbefore a MAC subPDU comprising padding.

In an example, a MAC entity of a base station may transmit one or moreMAC CEs to a MAC entity of a wireless device. FIG. 19 shows an exampleof multiple LCIDs that may be associated with the one or more MAC CEs.The one or more MAC CEs comprise at least one of: a SP ZP CSI-RSResource Set Activation/Deactivation MAC CE, a PUCCH spatial relationActivation/Deactivation MAC CE, a SP SRS Activation/Deactivation MAC CE,a SP CSI reporting on PUCCH Activation/Deactivation MAC CE, a TCI StateIndication for UE-specific PDCCH MAC CE, a TCI State Indication forUE-specific PDSCH MAC CE, an Aperiodic CSI Trigger State SubselectionMAC CE, a SP CSI-RS/CSI-IM Resource Set Activation/Deactivation MAC CE,a UE contention resolution identity MAC CE, a timing advance command MACCE, a DRX command MAC CE, a Long DRX command MAC CE, an SCellactivation/deactivation MAC CE (1 Octet), an SCellactivation/deactivation MAC CE (4 Octet), and/or a duplicationactivation/deactivation MAC CE. In an example, a MAC CE, such as a MACCE transmitted by a MAC entity of a base station to a MAC entity of awireless device, may have an LCID in the MAC subheader corresponding tothe MAC CE. Different MAC CE may have different LCID in the MACsubheader corresponding to the MAC CE. For example, an LCID given by111011 in a MAC subheader may indicate that a MAC CE associated with theMAC subheader is a long DRX command MAC CE.

In an example, the MAC entity of the wireless device may transmit to theMAC entity of the base station one or more MAC CEs. FIG. 20 shows anexample of the one or more MAC CEs. The one or more MAC CEs may compriseat least one of: a short buffer status report (BSR) MAC CE, a long BSRMAC CE, a C-RNTI MAC CE, a configured grant confirmation MAC CE, asingle entry PHR MAC CE, a multiple entry PHR MAC CE, a short truncatedBSR, and/or a long truncated BSR. In an example, a MAC CE may have anLCID in the MAC subheader corresponding to the MAC CE. Different MAC CEmay have different LCID in the MAC subheader corresponding to the MACCE. For example, an LCID given by 111011 in a MAC subheader may indicatethat a MAC CE associated with the MAC subheader is a short-truncatedcommand MAC CE.

In carrier aggregation (CA), two or more component carriers (CCs) may beaggregated. A wireless device may simultaneously receive or transmit onone or more CCs, depending on capabilities of the wireless device, usingthe technique of CA. In an embodiment, a wireless device may support CAfor contiguous CCs and/or for non-contiguous CCs. CCs may be organizedinto cells. For example, CCs may be organized into one primary cell(PCell) and one or more secondary cells (SCells). When configured withCA, a wireless device may have one RRC connection with a network. Duringan RRC connection establishment/re-establishment/handover, a cellproviding NAS mobility information may be a serving cell. During an RRCconnection re-establishment/handover procedure, a cell providing asecurity input may be a serving cell. In an example, the serving cellmay denote a PCell. In an example, a base station may transmit, to awireless device, one or more messages comprising configurationparameters of a plurality of one or more SCells, depending oncapabilities of the wireless device.

When configured with CA, a base station and/or a wireless device mayemploy an activation/deactivation mechanism of an SCell to improvebattery or power consumption of the wireless device. When a wirelessdevice is configured with one or more SCells, a base station mayactivate or deactivate at least one of the one or more SCells. Uponconfiguration of an SCell, the SCell may be deactivated unless an SCellstate associated with the SCell is set to “activated” or “dormant”.

A wireless device may activate/deactivate an SCell in response toreceiving an SCell Activation/Deactivation MAC CE. In an example, a basestation may transmit, to a wireless device, one or more messagescomprising an SCell timer (e.g., sCellDeactivationTimer). In an example,a wireless device may deactivate an SCell in response to an expiry ofthe SCell timer.

When a wireless device receives an SCell Activation/Deactivation MAC CEactivating an SCell, the wireless device may activate the SCell. Inresponse to the activating the SCell, the wireless device may performoperations comprising SRS transmissions on the SCell; CQI/PMI/RI/CRIreporting for the SCell; PDCCH monitoring on the SCell; PDCCH monitoringfor the SCell; and/or PUCCH transmissions on the SCell. In response tothe activating the SCell, the wireless device may start or restart afirst SCell timer (e.g., sCellDeactivationTimer) associated with theSCell. The wireless device may start or restart the first SCell timer inthe slot when the SCell Activation/Deactivation MAC CE activating theSCell has been received. In an example, in response to the activatingthe SCell, the wireless device may (re-)initialize one or more suspendedconfigured uplink grants of a configured grant Type 1 associated withthe SCell according to a stored configuration. In an example, inresponse to the activating the SCell, the wireless device may triggerPHR.

When a wireless device receives an SCell Activation/Deactivation MAC CEdeactivating an activated SCell, the wireless device may deactivate theactivated SCell. In an example, when a first SCell timer (e.g.,sCellDeactivationTimer) associated with an activated SCell expires, thewireless device may deactivate the activated SCell. In response to thedeactivating the activated SCell, the wireless device may stop the firstSCell timer associated with the activated SCell. In an example, inresponse to the deactivating the activated SCell, the wireless devicemay clear one or more configured downlink assignments and/or one or moreconfigured uplink grants of a configured uplink grant Type 2 associatedwith the activated SCell. In an example, in response to the deactivatingthe activated SCell, the wireless device may: suspend one or moreconfigured uplink grants of a configured uplink grant Type 1 associatedwith the activated SCell; and/or flush HARQ buffers associated with theactivated SCell.

When an SCell is deactivated, a wireless device may not performoperations comprising: transmitting SRS on the SCell; reportingCQI/PMI/RI/CRI for the SCell; transmitting on UL-SCH on the SCell;transmitting on RACH on the SCell; monitoring at least one first PDCCHon the SCell; monitoring at least one second PDCCH for the SCell; and/ortransmitting a PUCCH on the SCell. When at least one first PDCCH on anactivated SCell indicates an uplink grant or a downlink assignment, awireless device may restart a first SCell timer (e.g.,sCellDeactivationTimer) associated with the activated SCell. In anexample, when at least one second PDCCH on a serving cell (e.g. a PCellor an SCell configured with PUCCH, i.e. PUCCH SCell) scheduling theactivated SCell indicates an uplink grant or a downlink assignment forthe activated SCell, a wireless device may restart the first SCell timer(e.g., sCellDeactivationTimer) associated with the activated SCell. Inan example, when an SCell is deactivated, if there is an ongoing randomaccess procedure on the SCell, a wireless device may abort the ongoingrandom access procedure on the SCell.

FIG. 21A shows an example of an SCell Activation/Deactivation MAC CE ofone octet. A first MAC PDU subheader with a first LCID (e.g., ‘111010’as shown in FIG. 19 ) may identify the SCell Activation/Deactivation MACCE of one octet. The SCell Activation/Deactivation MAC CE of one octetmay have a fixed size. The SCell Activation/Deactivation MAC CE of oneoctet may comprise a single octet. The single octet may comprise a firstnumber of C-fields (e.g. seven) and a second number of R-fields (e.g.,one). FIG. 21B shows an example of an SCell Activation/Deactivation MACCE of four octets. A second MAC PDU subheader with a second LCID (e.g.,‘111001’ as shown in FIG. 19 ) may identify the SCellActivation/Deactivation MAC CE of four octets. The SCellActivation/Deactivation MAC CE of four octets may have a fixed size. TheSCell Activation/Deactivation MAC CE of four octets may comprise fouroctets. The four octets may comprise a third number of C-fields (e.g.,31) and a fourth number of R-fields (e.g., 1).

In FIG. 21A and/or FIG. 21B, a C_(i) field may indicate anactivation/deactivation status of an SCell with an SCell index i if anSCell with SCell index i is configured. In an example, when the C_(i)field is set to one, an SCell with an SCell index i may be activated. Inan example, when the C_(i) field is set to zero, an SCell with an SCellindex i may be deactivated. In an example, if there is no SCellconfigured with SCell index i, the wireless device may ignore the C_(i)field. In FIG. 21A and FIG. 21B, an R field may indicate a reserved bit.The R field may be set to zero.

A base station may configure a wireless device with uplink (UL)bandwidth parts (BWPs) and downlink (DL) BWPs to enable bandwidthadaptation (BA) on a PCell. If carrier aggregation is configured, thebase station may further configure the wireless device with at least DLBWP(s) (i.e., there may be no UL BWPs in the UL) to enable BA on anSCell. For the PCell, an initial active BWP may be a first BWP used forinitial access. For the SCell, a first active BWP may be a second BWPconfigured for the wireless device to operate on the SCell upon theSCell being activated. In paired spectrum (e.g. FDD), a base stationand/or a wireless device may independently switch a DL BWP and an ULBWP. In unpaired spectrum (e.g. TDD), a base station and/or a wirelessdevice may simultaneously switch a DL BWP and an UL BWP.

In an example, a base station and/or a wireless device may switch a BWPbetween configured BWPs by means of a DCI or a BWP inactivity timer.When the BWP inactivity timer is configured for a serving cell, the basestation and/or the wireless device may switch an active BWP to a defaultBWP in response to an expiry of the BWP inactivity timer associated withthe serving cell. The default BWP may be configured by the network. Inan example, for FDD systems, when configured with BA, one UL BWP foreach uplink carrier and one DL BWP may be active at a time in an activeserving cell. In an example, for TDD systems, one DL/UL BWP pair may beactive at a time in an active serving cell. Operating on the one UL BWPand the one DL BWP (or the one DL/UL pair) may improve wireless devicebattery consumption. BWPs other than the one active UL BWP and the oneactive DL BWP that the wireless device may work on may be deactivated.On deactivated BWPs, the wireless device may: not monitor PDCCH; and/ornot transmit on PUCCH, PRACH, and UL-SCH.

In an example, a serving cell may be configured with at most a firstnumber (e.g., four) of BWPs. In an example, for an activated servingcell, there may be one active BWP at any point in time. In an example, aBWP switching for a serving cell may be used to activate an inactive BWPand deactivate an active BWP at a time. In an example, the BWP switchingmay be controlled by a PDCCH indicating a downlink assignment or anuplink grant. In an example, the BWP switching may be controlled by aBWP inactivity timer (e.g., bwp-InactivityTimer). In an example, the BWPswitching may be controlled by a MAC entity in response to initiating aRandom Access procedure. Upon addition of a serving cell (e.g., anSpCell) or activation of an SCell, one BWP may be initially activewithout receiving a PDCCH indicating a downlink assignment or an uplinkgrant. The active BWP for a serving cell may be indicated by RRC and/orPDCCH. In an example, for unpaired spectrum, a DL BWP may be paired witha UL BWP, and BWP switching may be common for both UL and DL.

FIG. 22 shows an example of BWP switching on a cell (e.g., PCell orSCell). In an example, a wireless device may receive from a base stationat least one RRC message comprising parameters of a cell and one or moreBWPs associated with the cell. The RRC message may comprise: RRCconnection reconfiguration message (e.g., RRCReconfiguration); RRCconnection reestablishment message (e.g., RRCRestablishment); and/or RRCconnection setup message (e.g., RRCSetup). Among the one or more BWPs,at least one BWP may be configured as the first active BWP (e.g., BWP1), one BWP as the default BWP (e.g., BWP 0). The wireless device mayreceive a command (e.g., RRC message, MAC CE or DCI) to activate thecell at an n^(th) slot. The wireless device may start a celldeactivation timer (e.g., sCellDeactivationTimer), and start CSI relatedactions for the cell, and/or start CSI related actions for the firstactive BWP of the cell. The wireless device may start monitoring a PDCCHon BWP 1 in response to activating the cell.

In an example, the wireless device may start restart a BWP inactivitytimer (e.g., bwp-InactivityTimer) at an m^(th) slot in response toreceiving a DCI indicating DL assignment on BWP 1. The wireless devicemay switch back to the default BWP (e.g., BWP 0) as an active BWP whenthe BWP inactivity timer expires, at an s^(th) slot. The wireless devicemay deactivate the cell and/or stop the BWP inactivity timer when thesCellDeactivationTimer expires.

In an example, a MAC entity may apply normal operations on an active BWPfor an activated serving cell configured with a BWP comprising:transmitting on UL-SCH; transmitting on RACH; monitoring a PDCCH;transmitting PUCCH; receiving DL-SCH; and/or (re-) initializing anysuspended configured uplink grants of configured grant Type 1 accordingto a stored configuration, if any.

In an example, on an inactive BWP for each activated serving cellconfigured with a BWP, a MAC entity may: not transmit on UL-SCH; nottransmit on RACH; not monitor a PDCCH; not transmit PUCCH; not transmitSRS, not receive DL-SCH; clear any configured downlink assignment andconfigured uplink grant of configured grant Type 2; and/or suspend anyconfigured uplink grant of configured Type 1.

In an example, if a MAC entity receives a PDCCH for a BWP switching of aserving cell while a Random Access procedure associated with thisserving cell is not ongoing, a wireless device may perform the BWPswitching to a BWP indicated by the PDCCH. In an example, if a bandwidthpart indicator field is configured in DCI format 1_1, the bandwidth partindicator field value may indicate the active DL BWP, from theconfigured DL BWP set, for DL receptions. In an example, if a bandwidthpart indicator field is configured in DCI format 0_1, the bandwidth partindicator field value may indicate the active UL BWP, from theconfigured UL BWP set, for UL transmissions.

In an example, for a primary cell, a wireless device may be provided bya higher layer parameter Default-DL-BWP a default DL BWP among theconfigured DL BWPs. If a wireless device is not provided a default DLBWP by the higher layer parameter Default-DL-BWP, the default DL BWP isthe initial active DL BWP. In an example, a wireless device may beprovided by higher layer parameter bwp-InactivityTimer, a timer valuefor the primary cell. If configured, the wireless device may incrementthe timer, if running, every interval of 1 millisecond for frequencyrange 1 or every 0.5 milliseconds for frequency range 2 if the wirelessdevice may not detect a DCI format 1_1 for paired spectrum operation orif the wireless device may not detect a DCI format 1_1 or DCI format 0_1for unpaired spectrum operation during the interval.

In an example, if a wireless device is configured for a secondary cellwith higher layer parameter Default-DL-BWP indicating a default DL BWPamong the configured DL BWPs and the wireless device is configured withhigher layer parameter bwp-InactivityTimer indicating a timer value, thewireless device procedures on the secondary cell may be same as on theprimary cell using the timer value for the secondary cell and thedefault DL BWP for the secondary cell.

In an example, if a wireless device is configured by higher layerparameter Active-BWP-DL-SCell a first active DL BWP and by higher layerparameter Active-BWP-UL-SCell a first active UL BWP on a secondary cellor carrier, the wireless device may use the indicated DL BWP and theindicated UL BWP on the secondary cell as the respective first active DLBWP and first active UL BWP on the secondary cell or carrier.

In an example, a set of PDCCH candidates for a wireless device tomonitor is defined in terms of PDCCH search space sets. A search spaceset comprises a CSS set or a USS set. A wireless device monitors PDCCHcandidates in one or more of the following search spaces sets: aType0-PDCCH CSS set configured by pdcch-ConfigSIB1 in MIB or bysearchSpaceSIB1 in PDCCH-ConfigCommon or by searchSpaceZero inPDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI onthe primary cell of the MCG, a Type0-PDCCH CSS set configured bysearchSpaceOtherSystemInformation in PDCCH-ConfigCommon for a DCI formatwith CRC scrambled by a SI-RNTI on the primary cell of the MCG, aType1-PDCCH CSS set configured by ra-SearchSpace in PDCCH-ConfigCommonfor a DCI format with CRC scrambled by a RA-RNTI, a MsgB-RNTI, or aTC-RNTI on the primary cell, a Type2-PDCCH CSS set configured bypagingSearchSpace in PDCCH-ConfigCommon for a DCI format with CRCscrambled by a P-RNTI on the primary cell of the MCG, a Type3-PDCCH CSSset configured by SearchSpace in PDCCH-Config withsearchSpaceType=common for DCI formats with CRC scrambled by INT-RNTI,SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, orPS-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI, orCS-RNTI(s), and a USS set configured by SearchSpace in PDCCH-Config withsearchSpaceType=ue-Specific for DCI formats with CRC scrambled byC-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI(s), SL-RNTI, SL-CS-RNTI, orSL-L-CS-RNTI.

In an example, a wireless device determines a PDCCH monitoring occasionon an active DL BWP based on one or more PDCCH configuration parameterscomprising: a PDCCH monitoring periodicity, a PDCCH monitoring offset,and a PDCCH monitoring pattern within a slot. For a search space set(SSs), the wireless device determines that a PDCCH monitoringoccasion(s) exists in a slot with number n_(s,f) ^(μ) in a frame withnumber n_(f) if (n_(f)·N_(slot) ^(frame,μ)+n_(s,f) ^(μ)−o_(s)) modk_(s)=0. N_(slot) ^(frame,μ) is a number of slots in a frame whennumerology μ is configured. o_(s) is a slot offset indicated in thePDCCH configuration parameters. k_(s) is a PDCCH monitoring periodicityindicated in the PDCCH configuration parameters. The wireless devicemonitors PDCCH candidates for the search space set for T_(s) consecutiveslots, starting from slot n_(s,f) ^(μ), and does not monitor PDCCHcandidates for search space set s for the next k_(s)−T_(s) consecutiveslots. In an example, a USS at CCE aggregation level L∈{1, 2, 4, 8, 16}is defined by a set of PDCCH candidates for CCE aggregation level L.

In an example, a wireless device decides, for a search space set sassociated with CORESET p, CCE indexes for aggregation level Lcorresponding to PDCCH candidate m_(s,n) _(CI) of the search space setin slot n_(s,f) ^(μ) for an active DL BWP of a serving cellcorresponding to carrier indicator field value n_(CI) as

${{L \cdot \left\{ {\left( {Y_{p,n_{s,f}^{\mu}} + \left\lfloor \frac{m_{s,n_{CI}} \cdot N_{{CCE},p}}{L \cdot M_{s,\max}^{(L)}} \right\rfloor + n_{CI}} \right){mod}\left\lfloor {N_{{CCE},p}/L} \right\rfloor} \right\}} + i},$

where, Y_(p,n) _(s,f) _(μ) =0 for any CSS; Y_(p,n) _(s,f) _(μ)=(A_(p)·Y_(p,n) _(s,f) _(μ) ⁻¹) mod D for a USS, Y_(p,−1)=n_(RNTI)≠0,A_(p)=39827 for p mod 3=0, A_(p)=39829 for p mod 3=1, A_(p)=39839 for pmod 3=2, and D=65537; i=0, . . . , L−1; N_(CCE,p) is the number of CCEs,numbered from 0 to N_(CCE,p)−1, in CORESET p; n_(CI) is the carrierindicator field value if the wireless device is configured with acarrier indicator field by CrossCarrierSchedulingConfig for the servingcell on which PDCCH is monitored; otherwise, including for any CSS,n_(CI)=0; m_(s,n) _(CI) =0, . . . , M_(s,n) _(CI) ^((L))−1, whereM_(s,n) _(CI) ^((L)) is the number of PDCCH candidates the wirelessdevice is configured to monitor for aggregation level L of a searchspace set s for a serving cell corresponding to n_(CI); for any CSS,M_(s,max) ^((L))=M_(s,0) ^((L)); for a USS, M_(s,max) ^((L)) is themaximum of M_(s,n) _(CI) ^((L)) over all configured n_(CI) values for aCCE aggregation level L of search space set s; and the RNTI value usedfor n_(RNTI) is the C-RNTI.

In an example, a wireless device may monitor a set of PDCCH candidatesaccording to configuration parameters of a search space set comprising aplurality of search spaces (SSs). The wireless device may monitor a setof PDCCH candidates in one or more CORESETs for detecting one or moreDCIs. Monitoring may comprise decoding one or more PDCCH candidates ofthe set of the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common SSs, and/or number of PDCCH candidates in theUE-specific SSs) and possible (or configured) DCI formats. The decodingmay be referred to as blind decoding.

FIG. 23A shows an example of configuration parameters of a masterinformation block (MIB) of a cell (e.g., PCell). In an example, awireless device, based on receiving primary synchronization signal (PSS)and/or secondary synchronization signal (SSS), may receive a MIB via aPBCH. The configuration parameters of a MIB may comprise six bits(systemFrameNumber) of system frame number (SFN), subcarrier spacingindication (subCarrierSpacingCommon), a frequency domain offset(ssb-SubcarrierOffset) between SSB and overall resource block grid innumber of subcarriers, an indication (cellBarred) indicating whether thecell is bared, a DMRS position indication (dmrs-TypeA-Position)indicating position of DMRS, parameters of CORESET and SS of a PDCCH(pdcch-ConfigSIB1) comprising a common CORESET, a common search spaceand necessary PDCCH parameters.

In an example, a pdcch-ConfigSIB1 may comprise a first parameter (e.g.,controlResourceSetZero) indicating a common ControlResourceSet (CORESET)with ID #0 (e.g., CORESET#0) of an initial BWP of the cell.controlResourceSetZero may be an integer between 0 and 15. Each integerbetween 0 and 15 may identify a configuration of CORESET#0. FIG. 23Bshows an example of a configuration of CORESET#0. As shown in FIG. 23B,based on a value of the integer of controlResourceSetZero, a wirelessdevice may determine a SSB and CORESET#0 multiplexing pattern, a numberof RBs for CORESET#0, a number of symbols for CORESET#0, a RB offset forCORESET#0.

In an example, a pdcch-ConfigSIB1 may comprise a second parameter (e.g.,searchSpaceZero) common search space with ID #0 (e.g., SS#0) of theinitial BWP of the cell. searchSpaceZero may be an integer between 0 and15. Each integer between 0 and 15 may identify a configuration of SS#0.FIG. 23C shows an example of a configuration of SS#0. As shown in FIG.23C, based on a value of the integer of searchSpaceZero, a wirelessdevice may determine one or more parameters (e.g., O, M) for slotdetermination of PDCCH monitoring, a first symbol index for PDCCHmonitoring and/or a number of search spaces per slot.

In an example, based on receiving a MIB, a wireless device may monitorPDCCH via SS#0 of CORESET#0 for receiving a DCI scheduling a systeminformation block 1 (SIB1). The wireless device may receive the DCI withCRC scrambled with a system information radio network temporaryidentifier (SI-RNTI) dedicated for receiving the SIB1.

FIG. 24 shows an example of RRC configuration parameters of systeminformation block (SIB). A SIB (e.g., SIB1) may contain informationrelevant when evaluating if a wireless device is allowed to access acell and may define scheduling of other system information. A SIB maycontain radio resource configuration information that is common for allwireless devices and barring information applied to a unified accesscontrol. In an example, a base station may transmit to a wireless device(or a plurality of wireless devices) one or more SIB information. Asshown in FIG. 24 , parameters of the one or more SIB information maycomprise: one or more parameters (e.g., cellSelectionInfo) for cellselection related to a serving cell, one or more configurationparameters of a serving cell (e.g., in ServingCellConfigCommonSIB IE),and one or more other parameters. The ServingCellConfigCommonSIB IE maycomprise at least one of: common downlink parameters (e.g., inDownlinkConfigCommonSIB IE) of the serving cell, common uplinkparameters (e.g., in UplinkConfigCommonSIB IE) of the serving cell, andother parameters.

In an example a DownlinkConfigCommonSIB IE may comprise parameters of aninitial downlink BWP of the serving cell (e.g., SpCell). The parametersof the initial downlink BWP may be comprised in a BWP-DownlinkCommon IE(as shown in FIG. 25 ). The BWP-DownlinkCommon IE may be used toconfigure common parameters of a downlink BWP of the serving cell. Thebase station may configure the locationAndBandwidth so that the initialdownlink BWP contains the entire CORESET#0 of this serving cell in thefrequency domain. The wireless device may apply the locationAndBandwidthupon reception of this field (e.g. to determine the frequency positionof signals described in relation to this locationAndBandwidth) but itkeeps CORESET#0 until after reception ofRRCSetup/RRCResume/RRCReestablishment.

In an example, an UplinkConfigCommonSIB IE may comprise parameters of aninitial uplink BWP of the serving cell (e.g., SpCell). The parameters ofthe initial uplink BWP may be comprised in a BWP-UplinkCommon IE. TheBWP-UplinkCommon IE may be used to configure common parameters of anuplink BWP. The common parameters of an uplink BWP are “cell specific”.The base station may ensure the necessary alignment with correspondingparameters of other wireless devices. The common parameters of theinitial bandwidth part of the PCell may be provided via systeminformation. For all other serving cells, the base station may providethe common parameters via dedicated signaling.

FIG. 25 shows an example of RRC configuration parameters (e.g.,BWP-DownlinkCommon IE) in a of a downlink BWP of a serving cell. A basestation may transmit to a wireless device (or a plurality of wirelessdevices) one or more configuration parameters of a downlink BWP (e.g.,initial downlink BWP) of a serving cell. As shown in FIG. 25 , the oneor more configuration parameters of the downlink BWP may comprise: oneor more generic BWP parameters of the downlink BWP, one or more cellspecific parameters for PDCCH of the downlink BWP (e.g., inpdcch-ConfigCommon IE), one or more cell specific parameters for thePDSCH of this BWP (e.g., in pdsch-ConfigCommon IE), and one or moreother parameters. A pdcch-ConfigCommon IE may comprise parameters ofCOESET #0 (e.g., controlResourceSetZero) which can be used in any commonor UE-specific search spaces. A value of the controlResourceSetZero maybe interpreted like the corresponding bits in MIB pdcch-ConfigSIB1. Apdcch-ConfigCommon IE may comprise parameters (e.g., incommonControlResourceSet) of an additional common control resource setwhich may be configured and used for any common or UE-specific searchspace. If the network configures this field, it uses aControlResourceSetId other than 0 for this ControlResourceSet.Parameters of a control resource set may be implemented as shown in FIG.25 . The network configures the commonControlResourceSet in SIB1 so thatit is contained in the bandwidth of CORESET#0. A pdcch-ConfigCommon IEmay comprise parameters (e.g., in commonSearchSpaceList) of a list ofadditional common search spaces. Parameters of a search space may beimplemented based on example of FIG. 26 . A pdcch-ConfigCommon IE mayindicate, from a list of search spaces, a search space for paging (e.g.,pagingSearchSpace), a search space for random access procedure (e.g.,ra-SearchSpace), a search space for SIB1 message (e.g.,searchSpaceSIB1), a common search space#0 (e.g., searchSpaceZero), andone or more other search spaces.

As shown in FIG. 25 , a control resource set (CORESET) may be associatedwith a CORESET index (e.g., ControlResourceSetId). The CORESET indexwith a value of 0 may identify a common CORESET configured in MIB and inServingCellConfigCommon (controlResourceSetZero) and may not be used inthe ControlResourceSet IE. The CORESET index with other values mayidentify CORESETs configured by dedicated signaling or in SIB1. ThecontrolResourceSetId is unique among the BWPs of a serving cell. ACORESET may be associated with coresetPoolIndex indicating an index of aCORESET pool for the CORESET. A CORESET may be associated with a timeduration parameter (e.g., duration) indicating contiguous time durationof the CORESET in number of symbols. In an example, as shown in FIG. 25, configuration parameters of a CORESET may comprise at least one of:frequency resource indication (e.g., frequencyDomainResources), aCCE-REG mapping type indicator (e.g., cce-REG-MappingType), a pluralityof TCI states, an indicator indicating whether a TCI is present in aDCI, and the like. The frequency resource indication, comprising anumber of bits (e.g., 45 bits), indicates frequency domain resources,each bit of the indication corresponding to a group of 6 RBs (a resourceblock group, or a RBG in this specification), with grouping startingfrom the first RB group in a BWP of a cell (e.g., SpCell, SCell). Thefirst (left-most/most significant) bit corresponds to the first RB groupin the BWP, and so on. A bit that is set to 1 indicates that an RBgroup, corresponding to the bit, belongs to the frequency domainresource of this CORESET. Bits corresponding to a group of RBs not fullycontained in the BWP within which the CORESET is configured are set tozero.

FIG. 26 shows an example of configuration of a search space (e.g.,SearchSpace IE). In an example, one or more search space configurationparameters of a search space may comprise at least one of: a searchspace ID (searchSpaceId), a control resource set ID(controlResourceSetId), a monitoring slot periodicity and offsetparameter (monitoringSlotPeriodicityAndOffset), a search space timeduration value (duration), a monitoring symbol indication(monitoringSymbolsWithinSlot), a number of candidates for an aggregationlevel (nrofCandidates), and/or a SS type indicating a common SS type ora UE-specific SS type (searchSpaceType). The monitoring slot periodicityand offset parameter may indicate slots (e.g. in a radio frame) and slotoffset (e.g., related to a starting of a radio frame) for PDCCHmonitoring. The monitoring symbol indication may indicate on whichsymbol(s) of a slot a wireless device may monitor PDCCH on the SS. Thecontrol resource set ID may identify a control resource set on which aSS may be located.

In an embodiment, a base station may transmit, or a wireless device mayreceive, a TB scheduled in a unicast transmission, a broadcasttransmission, a multicast transmission, or a combination thereof. FIG.27A and FIG. 27B shows examples of unicast transmission, broadcasttransmission and multicast transmission.

As shown in FIG. 27A, a first wireless device (e.g., WD1) may receivefrom a base station transport blocks (TBs) dedicated for the firstwireless device, and/or scheduled by a DCI with a first UE specific RNTI(e.g., C-RNTI, CS-RNTI, MCS-C-RNTI, etc.,). In the example shown in FIG.27A, second wireless devices (e.g., WD2, WD3, WD4 etc.) may not receivethe TBs dedicated for the first wireless device because the secondwireless devices are not configured with the first UE specific RNTI. Inan example, TBs dedicated for a wireless device may be referred to asunicast TBs. A PDSCH carrying a TB dedicated for the wireless device maybe referred to as a unicast PDSCH. A PDCCH (or a DCI) scheduling thededicated TB may be referred to a unicast PDCCH (or a unicast DCI). Inan example, transmitting a TB, to a wireless device and scheduled by aunicast DCI, may improve security and flexibility of the scheduling.

As shown in FIG. 27A, a wireless device may receive from a base stationmulticast TBs (or groupcast TBs), of a multicast service (e.g., MBS),which may be received by a group of wireless devices (e.g., WD2, WD3,WD4 etc.) in the coverage of the base station. To receive the multicastTBs, the group of wireless devices may be allocated/configured with agroup dedicated RNTI (e.g., G-RNTI or SC-RNTI, or MBS-RNTI). Based onthe configured group dedicated RNTI, the group of wireless devices maymonitor PDCCH for receiving a DCI with CRC scrambled by the groupdedicated RNTI, the DCI scheduling the multicast TBs. In an example, awireless device (e.g., WD1) that is not configured with the groupdedicated RNTI may not receive the multicast TBs. In an example, the MBSmay carry message of applications comprising at least one of: V2X,public safety, live video (e.g., concert or sport), IOT software update,industry applications, etc. An MBS carrying a type of application datamay be defined as an MBS session. Different MBS session may be used fordifferent applications. A wireless device interested in the MBS providedby the base station may indicate to the base station that the wirelessdevice is interested in the MBS service. The base station mayaccordingly transmit to the wireless device MBS configuration parameterscomprising a RNTI dedicated for receiving DCI scheduling the MBS TBs. Byallocating the dedicated RNTI to a wireless device for receiving theMBS, the base station may be aware of which wireless device, or how manywireless devices, subscribe to the MBS. The MBS is different frombroadcast message where the base station does not know which wirelessdevice, or how many wireless devices are receiving the broadcastmessage. In an example, a network operator may determine an MBStransmission strategy or price strategy based on a number of subscribersof the MBS by using the multicast/groupcast scheduling.

As shown in FIG. 27B, a wireless device may receive from a base stationbroadcast TBs which may be received by any wireless device in coverageof a base station. The broadcast TBs may comprise system informationmessage, paging information message, etc. In an example, when receivingbroadcasted system information, or paging information, any wirelessdevice in the cell may monitor a PDCCH for receiving a DCI with CRCscrambled by a predefined RNTI (e.g., SI-RNTI with predefined value as“FFFF” in hexa-decimal, or P-RNTI with predefined value as “FFFE” inhexa-decimal, etc.). Since the RNTIs, for receiving the DCI schedulingthe broadcasted message, are known (e.g., by being set to predefinedvalue) to any wireless device in the cell, any wireless device mayreceive the broadcasted message. In an example, by transmitting a systeminformation or paging message scheduled by a broadcast scheduling DCI toa group of wireless devices, a base station may improve signalingefficiency for the base station.

In an embodiment, a base station may transmit to a group of wirelessdevices, MBS TBs via a BWP of a plurality of BWPs of a cell.

FIG. 28A and FIG. 28B show examples of MBS configurations when multipleBWPs are configured in a cell.

As shown in FIG. 28A, a BWP used for the transmission of MBS TBs (e.g.,which may be referred to as MBS BWP in this specification) may beconfigured separately and/or independently from a BWP for transmissionof unicast TBs and/or broadcast TBs (e.g., which may be referred to asunicast BWP in this specification). An MBS BWP in this specification maybe defined as a BWP, of a cell, on which MBS PDCCH/PDSCH may betransmitted. A unicast BWP in this specification may be defined as aBWP, of a cell, on which unicast PDCCH/PDSCH (and/or broadcastPDCCH/PDSCH) may be transmitted.

In an example, a base station may transmit to a wireless device one ormore RRC messages comprising configuration parameters of a cellcomprising a plurality of BWPs. The one or more RRC messages mayindicate that a first set of the plurality of BWPs are dedicated asunicast BWPs (e.g., BWP n, BWP m, etc., used for unicast PDCCH/PDSCHtransmission, or broadcasted system information transmission, orbroadcasted paging message transmission). In an example, the one or moreRRC messages may indicate that a second set of the plurality of BWPs arededicated as MBS BWPs (e.g., BWP x, BWP y, etc., used for MBSPDCCH/PDSCH transmission). In an embodiment, different MBS (e.g., V2X,public safety, live video, IOT software update, industry applications,etc.), targeting to different groups of wireless devices, may beconfigured on different BWPs. An MBS BWP may be used for transmission ofdifferent MBS TBs associated with different MBS configurations (e.g.,V2X, public safety, live video, IOT software update, industryapplications, etc.). In an example, configuring separate BWP(s) for MBSfrom unicast BWP(s) may improve system throughput and reduce schedulinglimitation/impact on the unicast PDSCH scheduling. In an embodiment, tosupport configuring separate BWP(s) for MBS, a wireless device may berequired to support multiple active BWPs in a cell.

As shown in FIG. 28B, frequency resources used for the transmission ofMBS TBs may be configured within a BWP for transmission of unicast TBsand/or broadcast TBs. The frequency resources configured in the BWP maybe resource blocks common to a group of wireless devices configured withthe MBS. The BWP may be an initial BWP of a cell, or a first active BWPconfigured on the cell. The BWP may be any BWP, except a dormant BWP ofthe cell. In an embodiment, a number of frequency resource blocks withina unicast BWP may be dedicated for transmission of MBS PDCCH/PDSCH to agroup of wireless devices. In an example, the number of frequencyresource blocks (or a set of frequency resource blocks) and locations ofthose frequency resource blocks within the BWP may be configured by thebase station in the one or more RRC messages. The one or more RRCmessages may further indicate configuration parameters of PDCCH for theMBS (e.g., referred to as MBS PDCCH), where the MBS PDCCH may carry aDCI with CRC scrambled by an MBS-specific RNTI (e.g., MBS-RNTI, SC-RNTI,G-RNTI, etc.). The configuration parameters may indicate frequencyresource allocation and time domain allocation of a search space and/ora CORESET for reception of the MBS PDCCH) within bandwidth of theunicast BWP. In an example, frequency resource allocation and timedomain allocation of a search space and/or a CORESET may be implementedbased on examples of FIG. 25 and/or FIG. 26 .

In an embodiment, different MBS, targeting different groups of wirelessdevices, may be configured on different sets of frequency resourceblocks within a unicast BWP. As shown in FIG. 28B, frequency resourceblocks for an MBS may be allocated on different unicast BWPs. In anexample, configuring frequency resources for MBS within unicast BWP maysimplify implementation of a wireless device and reduce powerconsumption of a wireless device. In an example, by supportingconfiguring the frequency resource for MBS within the unicast BWP, awireless device may be required to support a single active BWP in acell.

In an example, a wireless device may receive downlink assignments, on aPDCCH (e.g., in a DCI), indicating that there is a transmission on adownlink shared channel (DL-SCH) for a MAC entity of the wireless deviceand provides HARQ information. The HARQ information may comprise a NewData Indicator (NDI), Transport Block size (TBS), Redundancy Version(RV), and HARQ process ID etc. A MAC entity of the wireless device maybe configured with a wireless device specific identifier (e.g., C-RNTI,TC-RNTI, or CS-RNTI). The MAC entity of the wireless device may monitorPDCCH for a PDCCH occasion and for a cell.

In an embodiment, the MAC entity may determine the NDI (a bit) to havebeen toggled if a downlink assignment (for a PDCCH occasion and a cell)has been received on a PDCCH for the MAC entity's C-RNTI/TC-RNTI and ifthis is the first downlink assignment for the TC-RNTI. The MAC entitymay determine the NDI to have been toggled regardless of the value ofthe NDI if the downlink assignment has been received on the PDCCH forthe MAC entity's C-RNTI/TC-RNTI, the downlink assignment is for the MACentity's C-RNTI, and a previous downlink assignment indicated to theHARQ entity of the same HARQ process was either a downlink assignmentreceived for the MAC entity's CS-RNTI or a configured downlinkassignment. Based on the determined NDI, the MAC entity may indicate thepresence of a downlink assignment and deliver the associated HARQinformation to the HARQ entity of the wireless device for the cell.

In an embodiment, if a wireless device receives, for a PDCCH occasionand for a cell, a downlink assignment on a PDCCH for the MAC entity'sCS-RNTI, the MAC entity may determine a NDI for a corresponding HARQprocess (based on the downlink assignment) not to have been toggled if aNDI in the received HARQ information (based on the downlink assignment)is 1. The wireless device may indicate the presence of the downlinkassignment for the cell and deliver the associated HARQ information tothe HARQ entity associated with the cell.

In an embodiment, if a wireless device receives, for a PDCCH occasionand for a cell, a downlink assignment on a PDCCH for the MAC entity'sCS-RNTI, the MAC entity may perform SPS activation/deactivation relatedactivations if an NDI in the received HARQ information (based on thedownlink assignment) is 0.

In an embodiment, a wireless device may be configured with a configureddownlink assignment on a cell. The wireless device may activate theconfigured downlink assignment based on the CS-RNTI of the MAC entity.Based on the configured downlink assignment being configured andactivated, if a PDSCH duration of the configured downlink assignment(referred to as a semi-persistent downlink assignment, or SPS in thisspecification) does not overlap with a PDSCH duration of a downlinkassignment received on the PDCCH (referred to as a dynamic downlinkassignment in this specification) for the cell, a MAC entity of thewireless device may instruct the physical layer to receive, in the PDSCHduration, TB on the DL-SCH according to the configured downlinkassignment and to deliver it to the HARQ entity associated with thecell. The MAC entity may set the HARQ Process ID to a HARQ Process IDassociated with the PDSCH duration. The MAC entity may determine an NDIbit, for a corresponding HARQ process, to have been toggled. The MACentity may indicate the presence of the configured downlink assignmentand deliver the stored HARQ information to the HARQ entity.

In an embodiment, for configured downlink assignments without a highlayer HARQ process ID offset value (e.g., harq-ProcID-Offset), awireless device may derive a HARQ Process ID associated with a slotwhere a DL transmission starts based on the following equation: HARQProcess ID=[floor (CURRENT_slot×10/(numberOfSlotsPerFrame×periodicity))]modulo nrofHARQ-Processes.CURRENT_slot=[(SFN×numberOfSlotsPerFrame)+slot number in the frame] andnumberOfSlotsPerFrame refers to the number of consecutive slots perframe. SFN may be a system frame number of the slot.

In an embodiment, for configured downlink assignments with a high layerHARQ process ID offset value (e.g., harq-ProcID-Offset), a wirelessdevice may derive a HARQ Process ID associated with a slot where a DLtransmission starts based on the following equation: HARQ ProcessID=[floor (CURRENT_slot×10/(numberOfSlotsPerFrame×periodicity))] modulonrofHARQ-Processes+harq-ProcID-Offset.CURRENT_slot=[(SFN×numberOfSlotsPerFrame)+slot number in the frame] andnumberOfSlotsPerFrame refers to the number of consecutive slots perframe. SFN may be a system frame number of the slot.

When the MAC entity needs to receive BCCH, the MAC entity may, based onthe scheduling information from RRC, may indicate a downlink assignmentand redundancy version for the dedicated broadcast HARQ process to theHARQ entity, if a downlink assignment for the PDCCH occasion has beenreceived on the PDCCH for the SI-RNTI.

A MAC entity of a wireless device may comprise a HARQ entity for eachserving cell. The HARQ entity may maintain a number of parallel HARQprocesses. The HARQ entity may direct HARQ information and associatedTBs received on the DL-SCH to the corresponding HARQ processes.

A HARQ process may support one TB when the physical layer is notconfigured for downlink spatial multiplexing. A HARQ process may supportone or two TBs when the physical layer is configured for downlinkspatial multiplexing. A HARQ process may be associated with a HARQprocess identifier (ID). A dedicated broadcast HARQ process is used fora broadcast logic channel (BCCH) transmission.

A MAC entity of a wireless device may allocate TB(s) received from aphysical layer of the wireless device and associated HARQ information toa HARQ process indicated by the associated HARQ information (e.g., NDI,TBS, RV, and HARQ process ID) in response to a downlink assignment beingindicated. The MAC entity may allocate the received TB(s) to a broadcastHARQ process in response to the downlink assignment being indicated forthe broadcast HARQ process.

FIG. 29 shows an example of a HARQ entity configured with multiple HARQprocesses, according to some embodiments. As shown in FIG. 29 a HARQentity may comprise a number of parallel HARQ processes (e.g., Process#m, Process #n, etc.). Process #m may be identified with a first HARQprocess identifier (e.g., m). Process #n may be identified with a secondHARQ process identifier (e.g., n). In an example, when receivingdownlink data from the base station, a wireless device may process TB 1in Process #m. The wireless device may process TB 2 in Process #n. Inresponse to TB 1 not being successfully decoded by a wireless device,the wireless device may store received data of TB1 in a soft buffer ofProcess #m. The wireless device may transmit a negative acknowledgement(NACK) for TB 1 to the base station. In response to the NACK, the basestation may retransmit TB 1. The wireless device may attempt to decodeTB 1 based on the stored data of TB 1 in the soft buffer and receiveddata in retransmission of TB 1. In an example embodiment, in response toTB 2 being successfully decoded, the wireless device may transmit apositive acknowledgement (ACK) for TB 2 to the base station. In responseto TB 2 being successfully decoded, the wireless device may deliverdecoded data (e.g., MAC PDU) to a disassembly and demultiplexing entityof the wireless device. In response to the received positiveacknowledgement, the base station may transmit a new transport block(e.g., TB 3) by using Process #n.

In an embodiment, when a transmission takes place for a HARQ process, aHARQ entity (e.g., of the wireless device) may deliver one or two (incase of downlink spatial multiplexing) TBs (received) and the associatedHARQ information to the HARQ process.

For a received TB and associated HARQ information, a HARQ process (ofthe HARQ entity of the wireless device) may determine a transmission(associated with the TB) to be a new transmission if a NDI has beentoggled compared to the value of the previous received transmissioncorresponding to the received TB, or if the HARQ process is equal to thebroadcast process and this is the first received transmission for the TBaccording to the system information schedule indicated by RRC, or ifthis is the first received transmission for this TB (e.g., there is noprevious NDI for the TB). Otherwise, the HARQ process may determine thetransmission (associated with TB) to be a retransmission. Based on thedetermining the transmission to be a new transmission, the MAC entitymay attempt to decode the received data. Based on the determining thetransmission to be a retransmission, the MAC entity may instruct thephysical layer to combine the received data with the data currently inthe soft buffer for the TB and attempt to decode the combined data ifthe data for the TB has not yet been successfully decoded.

If the data which the MAC entity attempts to decode is successfullydecoded for a TB, or if the data for the TB is successfully decodedbefore, the MAC entity may deliver the decoded MAC PDU to upper layersif a HARQ process is equal to the broadcast process. If the data whichthe MAC entity attempts to decode is successfully decoded for a TB, orif the data for the TB is successfully decoded before, the MAC entitymay deliver the decoded MAC PDU to the disassembly and demultiplexingentity if this is the first successful decoding of the data for the TB.

If the data which the MAC entity attempts to decode is unsuccessfullydecoded for a TB, and if the data for the TB is unsuccessfully decodedbefore, the MAC entity may instruct the physical layer to replace thedata in the soft buffer for the TB with the data which the MAC entityattempted to decode.

The MAC entity may not instruct the physical layer to generateacknowledgement(s) of the data in the TB if the HARQ process isassociated with a transmission indicated with a TC-RNTI and theContention Resolution is not yet successful, or if the HARQ process isassociated with a transmission indicated with a MSGB-RNTI and the RandomAccess procedure is not yet successfully completed, or if the HARQprocess is equal to the broadcast process, or if a timeAlignmentTimer,associated with a TAG containing the cell on which the HARQ feedback isto be transmitted, is stopped or expired. Otherwise, the MAC entity mayinstruct the physical layer to generate acknowledgement(s) of the datain the TB.

A MAC entity may ignore NDI received in all downlink assignments onPDCCH for its TC-RNTI when determining if NDI on PDCCH for its C-RNTIhas been toggled compared to the value in the previous transmission. Ifthe MAC entity receives a retransmission with a TB size different fromthe last TB size signaled for the TB, the wireless device's behavior maybe left up to the wireless device's implementation.

FIG. 30 shows an example of a downlink TB (re)transmission mechanismbased on a HARQ procedure, according to some embodiments. In an example,a base station (e.g., gNB) may transmit to a wireless device (e.g., UE),a first downlink control information (DCI) comprising a downlinkassignment and one or more HARQ information. The one or more HARQinformation may comprise a HARQ Process ID (e.g., Process ID=k as shownin FIG. 30 ), a first NDI value (e.g., 1^(st) NDI=1), and the like. Thephysical layer of the wireless device may receive the data of a first TBbased on the downlink assignment. The wireless device, before receivingthe first DCI, may have a current NDI value (e.g., current NDI=0 asshown in FIG. 30 ).

In response to receiving the first DCI, the wireless device maydetermine that the first NDI has been toggled in response to the firstNDI value (1) being different from the current NDI value (0). Inresponse to the first NDI being toggled, the MAC entity of the wirelessdevice may determine a transmission of the first TB to be a newtransmission, and attempt to decode the received data of the first TB.The MAC entity may not successfully decode the received data. Inresponse to not successfully decoding the received data, the MAC entitymay instruct the physical layer to replace a soft buffer for the firstTB with the data which the MAC entity attempted to decode. The MACentity may instruct the physical layer to generate a NACK for the datain the first TB. In an example, in response to not successfully decodingthe received data, the wireless device may transmit the NACK to the basestation.

In response to receiving the NACK, the base station may transmit asecond DCI indicating a retransmission of the first TB, wherein thesecond DCI comprise a same HARQ Process ID as the first HARQ Process ID,a second downlink assignment, a RV value, and a second NDI value (e.g.,2^(nd) NDI=1).

The UE may determine the second NDI is not toggled in response to thesecond NDI value (1) being equal to the first NDI value (1), which isnow the new current NDI value. The physical layer may receive the dataof the retransmitted first TB via the second downlink assignment. Inresponse to the second NDI not being toggled, the MAC entity of thewireless device may determine the transmission via the second downlinkassignment to be a retransmission of the first TB. In an example, thewireless device may attempt to decode the first TB based on the newlyreceived data of the first TB and the current data in the soft bufferassociated with the HARQ process identified by HARQ Process ID k.

In an example, the MAC entity may successfully decode the received dataof the first TB. In response to successfully decoding the received data,the MAC entity may deliver a decoded data (e.g., MAC PDU) to adisassembly and demultiplexing entity of the wireless device. The MACentity may instruct the physical layer to generate an ACK of the data inthe first TB. The wireless device may transmit the ACK for the first TBto the base station.

In an example, a wireless device may receive from a base station one ormore TBs of an MBS session. The MBS session may require higher QoS thana periodic broadcast message. Compared with the periodic broadcastmessage, an MBS session comprising V2X application data may requirelower latency transmission. Compared with periodic broadcast message, anMBS session comprising IOT industry application data may require higherreliability. Compared with periodic broadcast message, an MBS sessioncomprising live video application data may require higher throughput andhigher reliability, etc.

To meet the QoS requirement of transmission of an MBS TB, a base stationmay apply a HARQ mechanism for retransmission of the MBS TB when awireless device subscribed to the MBS session does not receive the MBSTB successfully. The base station may retransmit the MBS TB in a unicasttransmission or in a multicast transmission.

FIG. 31A and FIG. 31B show examples of unicast retransmission of an MBSTB and multicast retransmission of an MBS TB, according to someembodiments.

As shown in FIG. 31A, a wireless device, when subscribed to an MBSsession, may receive an initial transmission of an MBS TB (or a TB). Thewireless device may receive the initial transmission based on receivinga DCI with CRC scrambled by an MBS-RNTI associated with the MBS session.The wireless device may receive the DCI when the wireless device ismonitoring PDCCH on a search space (associated with a CORESET)configured for the MBS session. The wireless device may attempt todecode the MBS TB based on the MBS-RNTI. The wireless device may decodethe TB unsuccessfully (e.g., with incorrect CRC check). The wirelessdevice may buffer the received data for the TB based on unsuccessfullydecoding the TB.

As shown in FIG. 31A, the wireless device may transmit a HARQ NACKindicating that the wireless device decoded the TB unsuccessfully. Thebase station may, based on the received HARQ NACK, transmit a second DCIwith CRC scrambled by the MBS-RNTI. The second DCI may indicate aretransmission of the MBS TB. The second DCI is transmitted to a groupof wireless devices subscribed to the MBS session. The retransmission ofthe MBS TB is for the group of wireless devices. The wireless device,based on the transmitting the HARQ NACK, may monitor the PDCCH on thesearch space configured for the MBS session for receiving the second DCIindicating the retransmission of the MBS TB. The wireless device mayreceive the retransmitted MBS TB based on receiving the second DCI. Thewireless device may combine the first received data (e.g., the first TBinitialized received based on the 1^(st) DCI) and second received data(e.g., the newly received data for the MBS TB based on the 2^(nd) DCI).The wireless device may attempt to decode the combined first and seconddata for the MBS TB based on the MBS-RNTI.

In an example, the wireless device may decode the combined datasuccessfully. The wireless device may deliver decoded MAC PDU comprisedin the MBS TB to a disassembly and demultiplexing entity of the wirelessdevice.

In an example, the wireless device may decode the combined dataunsuccessfully. The wireless device, based on unsuccessfully decodingthe combined data, may determine to request retransmission based onexamples of the above embodiments.

Retransmission of a MBS TB in a multicast transmission may improvesignaling overhead, e.g., when multiple wireless devices, subscribed toan MBS session, request retransmission of the MBS TB in response to theMBS TB being unsuccessfully decoded by the multiple wireless devices.Retransmission of the MBS TB in a multicast transmission may reducemulticast transmission throughput because the base station mayretransmit the MBS TB in a multicast transmission when there is awireless device of the multiple wireless devices who does not correctlydecode the MBS TB even if one or more other wireless devices of themultiple wireless devices did correctly decode the MBS TB.

FIG. 31B shows an example of unicast retransmission of an MBS TB,according to some embodiments. A wireless device, when subscribed to anMBS session, may receive an initial transmission of an MBS TB (or a TB).The wireless device may receive the initial transmission based onreceiving a DCI with CRC scrambled by an MBS-RNTI associated with theMBS session. The wireless device may receive the DCI when the wirelessdevice is monitoring PDCCH on a search space (associated with a CORESET)configured for the MBS session. The wireless device may attempt todecode the MBS TB based on the MBS-RNTI. The wireless device may decodethe TB unsuccessfully. The wireless device may buffer the received datafor the TB based on the unsuccessfully decoding the TB.

As shown in FIG. 31B, the wireless device may transmit a HARQ NACKindicating that the wireless device decoded the TB unsuccessfully. Thebase station may, based on the received HARQ NACK, transmit a second DCIwith CRC scrambled by the C-RNTI. The second DCI may indicate aretransmission of the MBS TB in a unicast transmission. The second DCIis transmitted dedicatedly to the wireless device (not to secondwireless devices other than the wireless device). The retransmission ofthe MBS TB scheduled by the second DCI is transmitted dedicatedly to thewireless device. The wireless device may receive the retransmitted MBSTB based on receiving the second DCI. The wireless device may combinethe first received data (e.g., the initially received TB data based onthe 1^(st) DCI) and the second received data (e.g., the newly receivedTB data based on the 2^(nd) DCI) for the MBS TB. The wireless device mayattempt to decode the combined first and second data for the MBS TB.

In an example, the wireless device may decode the combined datasuccessfully. The wireless device may deliver decoded MAC PDU comprisedin the MBS TB to a disassembly and demultiplexing entity of the wirelessdevice.

In an example, the wireless device may decode the combined dataunsuccessfully. The wireless device, based on unsuccessfully decodingthe combined data, may determine to request retransmission based onexample of above embodiments.

Retransmission of an MBS TB in a unicast transmission may improvemulticast transmission throughput since the base station transmits newMBS TB (or does not perform retransmission of an old MBS TB) in eachmulticast transmission occasion. Retransmission of a MBS TB in a unicasttransmission may increase signaling overhead, e.g., when multiplewireless devices, subscribed to an MBS session, request retransmissionof the MBS TB and the base station may retransmit the MBS TB to each ofthe multiple wireless devices separately.

In an example, a wireless device may receive a multicast initialtransmission of an MBS TB and a multicast retransmission of the MBS TB.The wireless device may receive a multicast initial transmission of anMBS TB and a unicast retransmission of the MBS TB. The wireless device,by using existing technologies, may be required to support two types ofretransmissions, e.g., a multicast retransmission type and a unicastretransmission type. The wireless device, by supporting bothretransmission types, may be required to monitor a first PDCCH on an MBSdedicated search space for receiving a first DCI for the multicastretransmission and monitor a second PDCCH on a unicast search space forreceiving a second DCI for the unicast retransmission. Monitoring bothPDCCHs for a retransmission of an MBS may increase power consumption ofa wireless device and/or increase implementation complexity of thewireless device. There is a need to efficiently handle reception ofretransmissions of an MBS TB to reduce power consumption of a wirelessdevice.

In existing technologies, a base station may transmit a unicast DCIindicating a retransmission of an MBS TB (initially scheduled by amulticast DCI), e.g., when the base station receives a HARQ feedbackindicating a failure of reception of the MBS TB. The base station maytransmit a unicast DCI indicating the retransmission of the MBS TB,based on: the unicast DCI and the multicast DCI comprising a same HARQprocess ID, and interlocking a first NDI of the multicast DCI and asecond NDI of the unicast DCI (e.g., by not toggling the second NDIcomparing with the first NDI). In existing technologies, the unicast DCIand the multicast DCI may be received, by a wireless device, in a samesearch space, or in a same control resource set of a cell. comparing thetwo DCIs (e.g., comparing two NDIs and/or two HARQ process IDs) receivedin the same search space or in the same control resource set may not bea problem for a wireless device in a cell with narrow bandwidth.Similarly, combining two data (one received with a multicasttransmission and another one received with a unicast transmission)received in a same frequency range of a cell may not be a problem for awireless device in a cell with narrow bandwidth.

In a NR system, when a cell with large bandwidth is divided intomultiple BWPs (e.g., as shown in FIG. 9 ) and frequency resources forMBS transmissions are separately configured, within a unicast BWP, fromfrequency resources for unicast transmissions (e.g., as shown in FIG.28B), a wireless device, by implementing existing technologies, may notbe able to decode a MBS TB based on a soft combination of first data(being scrambled by a MBS RNTI) and second data (being scrambled by aC-RNTI). The wireless device, based on existing technologies, maymistakenly determine whether a unicast DCI received in a unicast searchspace of a BWP is for a unicast TB or for a retransmission of an MBS TBwhich was previously scheduled by an MBS DCI received in an MBS searchspace. The MBS search space may be configured with common frequencyresources, associated with the MBS, within a unicast BWP. The unicastsearch space may be configured, (e.g., outside of the common frequencyresource), and within the unicast BWP. Existing technologies may reducesystem throughput of a cell (or a BWP) supporting both unicasttransmissions and MBS transmissions. There is a need to efficientlyhandle reception of retransmissions of an MBS TB to reduce powerconsumption of a wireless device when the MBS TB is initially scheduledby an MBS DCI in a common search space and the MBS TB is retransmittedbased on unicast DCI in a unicast search space.

In an example embodiment, a base station may transmit to a wirelessdevice one or more configuration parameters of an MBS session. Theconfiguration parameters may comprise an MBS dedicated RNTI (e.g.,MBS-RNTI, G-RNTI, SC-RNTI, etc.) associated with the MBS session. Theconfiguration parameters may comprise a retransmission type parameterindicating whether a unicast retransmission or a multicastretransmission will be used by the base station for an MBS TB. Thewireless device may receive a multicast initial transmission of an MBSTB and may not successfully decode the MBS TB. The wireless device maytransmit, to the base station, a HARQ NACK indicating that the wirelessdevice does not successfully decode the MBS TB.

In an example embodiment, based on the retransmission type indicatingthat the unicast retransmission is used for an MBS TB, the wirelessdevice may monitor a PDCCH (e.g., via a unicast search space) forreceiving a DCI (with CRC scrambled by C-RNTI) scheduling a unicastretransmission of the MBS TB. The wireless device may combine a unicastretransmission of the MBS TB (scrambled by C-RNTI) and a multicastinitial transmission of the MBS TB (scrambled by MBS-RNTI) and decodethe combined data for the MBS TB.

In an example embodiment, based on the retransmission type indicatingthat the multicast retransmission is scheduled for an MBS TB, thewireless device may monitor a PDCCH (e.g., via a common search spaceassociated with the MBS) for receiving a DCI (with CRC scrambled byMBS-RNTI) scheduling a multicast retransmission of the MBS TB. Thewireless device may combine a multicast retransmission of the MBS TB(scrambled by MBS-RNTI) and a multicast initial transmission of the MBSTB (scrambled by MBS-RNTI).

In an example embodiment, based on the retransmission type indicatingthat the multicast retransmission is used for an MBS TB, the wirelessdevice may monitor a PDCCH for receiving a DCI (with CRC scrambled by anMBS-C-RNTI) scheduling a multicast retransmission of the MBS TB. TheMBS-C-RNTI may be configured by the base station for schedulingretransmission of an MBS TB in a multicast transmission. The MBS-C-RNTImay be separately or independently configured from the MBS-RNTI forinitial transmission of the MBS TB. In an example embodiment, when thewireless device unsuccessfully decodes an MBS TB scheduled by a DCI withCRC scrambled by the MBS-RNTI, the wireless device may monitor PDCCH forreceiving a second DCI with CRC scrambled by the MBS-C-RNTI forretransmission of the MBS TB.

In an example embodiment, the retransmission type may be configured perMBS session, per BWP, per cell, per cell group, or any combinationthereof.

In an example embodiment, the retransmission type may be configured perMBS session. A base station may transmit the configuration parameters ofa plurality of MBS sessions, each MBS session being associated with aretransmission type. The retransmission type may indicate whether aunicast retransmission or a multicast retransmission is used for an MBSTB.

In an example embodiment, the retransmission type may be configured perBWP. A base station may transmit the configuration parameters of aplurality of BWPs of a cell. Each BWP may be associated with one or moreMBS session. Each BWP may be configured with a retransmission type forthe one or more MBS session, the retransmission type indicating whethera unicast retransmission or a multicast retransmission is used for anMBS TB of the one or more MBS session.

In an example embodiment, the retransmission type may be configured percell. A base station may transmit the configuration parameters of aplurality of cells (e.g., PCell or SCell). Each cell may be associatedwith one or more MBS session. Each cell may be configured with aretransmission type for the one or more MBS session, the retransmissiontype indicating whether a unicast retransmission or a multicastretransmission is used for an MBS TB of the one or more MBS session.

In an example embodiment, the retransmission type may be indicated in aDCI. The DCI may be a DCI (e.g., with CRC scrambled by MBS-RNTI)scheduling an initial transmission of an MBS TB. The wireless device maydetermine a retransmission type for a retransmission of an MBS TB basedon the retransmission type in the DCI.

In an example embodiment, a wireless device may determine aretransmission type based on RRC message and a DCI. The wireless devicemay determine a retransmission type based on RRC message comprising theretransmission type and the DCI not comprising the retransmission type.The wireless device may determine a retransmission type based on RRCmessage not comprising the retransmission type and the DCI comprisingthe retransmission type. The wireless device may determine aretransmission type based on overriding a first retransmission typeindicated in RRC message by a second retransmission type indicated inDCI.

FIG. 32 shows an example of retransmission of an MBS TB, according tosome embodiments. In an example embodiment, a base station may transmit,and/or a wireless device may receive, one or more RRC messagescomprising configuration parameters of an MBS session. The configurationparameters may comprise an MBS dedicated RNTI (e.g., MBS-RNTI,MBS-C-RNTI, G-RNTI, SC-RNTI, etc.) associated with the MBS session. Theconfiguration parameters may comprise a retransmission type (mode,configuration, indication, etc.) parameter indicating whether a unicastretransmission or a multicast retransmission will be used by the basestation for an MBS TB retransmission. The one or more RRC message mayfurther indicate configuration parameters of frequency resources for theMBS session (e.g., based on the example embodiments described withrespect to FIG. 28A and/or FIG. 28B). The one or more RRC message mayfurther indicate configuration parameters of PDCCH for the MBS (e.g.,referred to as MBS PDCCH), where the MBS PDCCH may carry a DCI with CRCscrambled by an MBS specific/dedicated RNTI (e.g., MBS-RNTI, SC-RNTI,G-RNTI, etc.). In this specification, the MBS specific/dedicated RNTI,the MBS-RNTI, the SC-RNTI and the G-RNTI may be exchangeable in terms ofits being different from C-RNTI. The configuration parameters mayindicate frequency resource allocation and time domain allocation of asearch space and/or a CORESET for reception of the MBS PDCCH in a BWP.The search space may be a common search space as a contrast to aUE-specific search space. A common search space and/or a UE-specificsearch space may be implemented based on example embodiments describedabove with respect to FIG. 22 . In an example, frequency resourceallocation and time domain allocation of a search space and/or a CORESETmay be implemented based on the example embodiments described withrespect to FIG. 25 and/or FIG. 26 .

In an example embodiment, the one or more RRC messages may furthercomprise a C-RNTI (CS-RNTI, MCS-C-RNTI, etc.) associated with thewireless device. The one or more RRC message may further indicateconfiguration parameters of PDCCH for unicast transmission (e.g.,referred to as unicast PDCCH), where the unicast PDCCH may carry a DCIwith CRC scrambled by a wireless device specific RNTI (e.g., C-RNTI,CS-RNTI, MCS-C-RNTI, etc.). The configuration parameters may indicatefrequency resource allocation and time domain allocation of a searchspace and/or a CORESET for reception of the unicast PDCCH in a BWP. Inan example, frequency resource allocation and time domain allocation ofa search space and/or a CORESET may be implemented based on the exampleembodiments described with respect to FIG. 25 and/or FIG. 26 .

In an example embodiment, the wireless device may receive a DCI (notshown in FIG. 32 ) with CRC scrambled by an MBS-RNTI via an MBS PDCCH inthe BWP, wherein the DCI indicates downlink assignment of MBS PDSCHresources for initial transmission of an MBS TB. The MBS TB, beingscrambled by the MBS-RNTI, is transmitted to a group of wireless devicesconfigured with the MBS-RNTI. As shown in FIG. 32 , the wireless devicemay receive a multicast initial transmission (1^(st) data) of an MBS TBbased on the DCI. The DCI (or the group common DCI) and the MBS PDSCH(or the group common PDSCH) may be received in the common frequencyresources associated with the MBS within the BWP. The wireless devicemay not successfully decode the MBS TB.

In an example embodiment, the DCI may be one of a legacy DCI format(e.g., DCI format 1_0/1_1/1_2) or a new DCI format different from thelegacy DCI formats. The DCI may have less DCI payloads than the legacyDCI format 1_0. In an example, the DCI may comprise at least one of:time domain resource assignment indication, VRB-to-PRB mappingindication, MCS indication, NDI, redundancy version, HARQ processnumber, PUCCH resource indicator, PDSCH-to-HARQ_feedback timingindicator, ChannelAccess-CPext, etc. In an example embodiment, one ormore DCI fields (e.g., NDI, redundancy version, PUCCH resourceindicator, PDSCH-to-HARQ_feedback timing indicator, and/orChannelAccess-CPext, etc.) may be absent in the DCI for MBS PDSCHscheduling.

As shown in FIG. 32 , the wireless device may transmit a HARQ NACKsignaling indicating that the wireless device did not successfullydecode the MBS TB. The wireless device may transmit the HARQ NACKsignaling comprised in a UCI via a PUCCH resource.

As shown in FIG. 32 , the wireless device may determine whether theretransmission type parameter indicates a unicast retransmission type ora multicast retransmission type. In response to the retransmission typeparameter indicating the unicast retransmission type, the wirelessdevice may monitor the unicast PDCCH, on the search space/CORESEassociated with the unicast PDCCH, for receiving a first DCI (with CRCscrambled by the C-RNTI/CS-RNTI) scheduling a unicast retransmission ofthe MBS TB. Based on the monitoring of the unicast PDCCH, the wirelessdevice may receive the first DCI. The wireless device may receive theunicast retransmitted MBS TB (2^(nd) data in FIG. 32 ). The wirelessdevice may combine the initial transmitted data (1^(st) data in FIG. 32) and the retransmitted data (2^(nd) data in FIG. 32 ). Based on thecombining, the wireless device may decode the MBS TB. In an example, thewireless device may determine whether a unicast PDCCH schedules aretransmission of the MBS TB or an initial transmission of a unicast TB,based on example embodiments of FIG. 33 , FIG. 34 , FIG. 35 and/or FIG.36 .

In an example embodiment, the wireless device may determine theretransmission type parameter indicates a multicast retransmission type.In response to the retransmission type parameter indicating themulticast retransmission type, the wireless device may monitor themulticast PDCCH, on the search space/CORESE associated with themulticast PDCCH, for receiving a second DCI (with CRC scrambled by theMBS-RNTI) scheduling a multicast retransmission of the MBS TB. Based onthe monitoring of the multicast PDCCH, the wireless device may receivethe second DCI. The wireless device may receive the multicastretransmitted MBS TB (2^(nd) data in FIG. 32 ). The wireless device maycombine the initial transmitted data (1^(st) data in FIG. 32 ) and theretransmitted data (2^(nd) data in FIG. 32 ). Based on the combining,the wireless device may decode the MBS TB.

Example embodiments as described with respect to FIG. 32 may improvesignaling overhead for retransmission of an MBS TB. Example embodimentsmay improve multicast throughput and/or reduce implementation complexityof a wireless device for receiving a retransmission of an MBS TB.

In an example embodiment, a base station may determine a retransmissiontype for an MBS TB of a MBS session, based on one or more criterioncomprising at least one of: a number of wireless devices subscribed tothe MBS session, a frequency resource configuration for the MBS session,QoS requirements for the MBS session, a wireless device capability forprocessing retransmission of a MBS TB, etc. In an example embodiment,the base station may determine a unicast retransmission type for an MBSTB, e.g., when the base station determines a number of wireless devicessubscribed to an MBS session is less than a threshold. The base stationmay determine a multicast retransmission type for an MBS TB, e.g., whenthe base station determines a number of wireless devices subscribed toan MBS session is greater than a threshold. In an example embodiment,the base station may determine a unicast retransmission type for an MBSTB, e.g., when the base station determines frequency resources of theMBS session are within a unicast BWP. The base station may determine amulticast retransmission type for an MBS TB, e.g., when the base stationdetermines that an MBS dedicated BWP is configured on a cell and the MBSdedicated BWP is different from a unicast BWP of the cell.

In an example embodiment, a wireless device may transmit to the basestation a wireless device capability message comprising a retransmissiontype indication indicating whether the wireless device supportsretransmission(s) of an MBS TB via unicast transmission(s) orretransmission(s) of the MBS TB via multicast transmission(s). Theretransmission type indication may be indicated per MBS session, percell, per cell group, per frequency range, etc. The wireless devicecapability message may further indicate whether the wireless devicesupports a unicast retransmission of an MBS TB being scrambled by anMBS-RNTI associated with an MBS session or the wireless device supportsthe unicast retransmission of the MBS TB being scrambled by a C-RNTIassociated with the wireless device. The wireless device may transmitthe wireless device capability message in response to receiving from abase station a wireless device capability request message. Based on thereceived wireless device capability message, the base station maytransmit to the wireless device the retransmission type parameter.

In an example embodiment, the retransmission type may be indicated in aDCI. The DCI may be a DCI (e.g., with CRC scrambled by MBS-RNTI)scheduling an initial transmission of an MBS TB.

In an example embodiment, a DCI (e.g., with new DCI format differentfrom a legacy DCI format 1_0/1_1/1_2), comprising the retransmissiontype field, may indicate whether the MBS TB will be retransmitted in aunicast transmission or in a multicast transmission in caseretransmission is requested. The wireless device may determine aretransmission type for a retransmission of an MBS TB based on theretransmission type in the DCI.

In an example embodiment, a DCI (e.g., with a legacy DCI format), withone or more DCI fields (e.g., downlink assignment index,PDSCH-to-HARQ_feedback timing indicator, etc.) being set to predefinedvalues, may indicate whether the MBS TB will be retransmitted in aunicast transmission or in a multicast transmission in caseretransmission is requested. The wireless device may determine aretransmission type for a retransmission of an MBS TB based on the oneor more values of the one or more DCI fields of the DCI.

In an example embodiment, the base station may determine a RNTI for datascrambling for a retransmission of a MBS TB, based on at least one of: anumber of wireless devices subscribed to the MBS session, frequencyresource configuration for the MBS session, QoS requirements for the MBSsession, a wireless device's capability etc. In an example embodiment,for retransmission of a MBS TB, the base station may scramble the MBS TBwith an MBS-RNTI in response to determining the retransmission is amulticast retransmission type. The base station may scramble the MBS TBwith an MBS-C-RNTI in response to determining the retransmission is amulticast retransmission type, wherein the MBS-C-RNTI is different fromthe MBS-RNTI configured for initial transmission. The base station mayscramble the MBS TB with a C-RNTI in response to determining theretransmission is a unicast retransmission type. In an exampleembodiment, the base station may scramble the MBS TB with the MBS-RNTIin response to determining the retransmission is a unicastretransmission type.

In an example embodiment, in response to a unicast retransmission of anMBS TB being scrambled by an MBS-RNTI, a wireless device may combine aninitial transmission of the MBS TB scrambled by an MBS-RNTI and aretransmission of the MBS TB scrambled by the MBS-RNTI. The wirelessdevice may decode the combined data for the MBS TB. Retransmitting of anMBS TB in a unicast transmission and scrambled with an MBS-RNTI maysimplify decoding complexity of the wireless device.

In an example embodiment, in response to a unicast retransmission of anMBS TB being scrambled by a C-RNTI, a wireless device may combine aninitial transmission of the MBS TB scrambled by an MBS-RNTI and aretransmission of the MBS TB scrambled by the C-RNTI. The wirelessdevice may decode the combined data for the MBS TB. Retransmitting of anMBS TB in a unicast transmission and scrambled with a C-RNTI may improvetransmission security of the MBS TB.

In an example embodiment, when a base station determines a unicastretransmission of an MBS TB of an MBS session, the base station mayscramble the MBS TB with an MBS-RNTI associated with the MBS session andretransmit the scrambled MBS TB in a unicast PDSCH resource. The basestation may scramble a number of bits (e.g., b^((q))(0), . . . ,b^((q))(M_(bit) ^((q))−1)) of a codeword of the MBS TB according to{tilde over (b)}^((q))(i)=(b^((q))(i)+c^((q))(i)) mod 2. Scramblingsequence c^((q))(i) may be generated according to the followingequation:

c(n)=(x ₁(n+N _(C))+x ₂(n+N _(C)))mod2

x ₁(n+31)=(x ₁(n+3)+x ₁(n))mod2

x ₂(n+31)=(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n))mod2

where N_(C)=1600 and the first m-sequence x₁(n) shall be initializedwith x₁(0)=1,x₁(n)=0, n=1,2, . . . ,30.

In an example embodiment, a scrambling sequence generator for thescrambling sequence may be initialized withc_(init)=n_(RNTI)·2¹⁵+q·2¹⁴+n_(ID), where n_(RNTI) corresponds to theMBS-RNTI associated with an MBS session. n_(ID) may be equal to a datascrambling identity configured for the MBS PDSCH or for the MBS session.n_(ID) (e.g., a new dataScrambingIdentityMBS-PDSCH IE configured inconfiguration parameters of the MBS configuration) may be differently orseparately configured from a higher-layer parameterdataScramblingIdentityPDSCH configured for a unicast PDSCH transmission.Separately configuration nips for MBS PDSCH (or group common PDSCHdedicated for the MBS) and unicast PDSCH may increase transmissionsecurity for the MBS session.

In an example, a higher-layer parameter dataScramblingIdentityPDSCH maybe applied for determination of n ID when a DCI scheduling the unicastPDSCH transmission is CRC scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI,and the DCI is not a DCI format 1_0 received in a common search space.For unicast PDSCH scheduled by a DCI, n_(ID) may be equal to a cellidentifier of the cell if the higher-layer parameterdataScramblingIdentityPDSCH is not configured, or if the RNTI for theDCI does not equal the C-RNTI, MCS-C-RNTI, or CS-RNTI, or if the DCI isa DCI format 1_0 via a common search space.

Based on the example embodiment, a base station may transmit, and/or awireless device may receive RRC messages comprising first configurationparameters of an MBS session and second configuration parameters forunicast transmissions. The first configuration parameter and/or thesecond configuration parameters may be implemented based on exampleembodiments described above with respect to FIG. 28B, FIG. 31A, FIG.31B, and/or FIG. 32 . In an example embodiment, the first configurationparameters may indicate that common frequency resources, of the MBSsession, are configured within a BWP (e.g., based on example embodimentsdescribed above with respect to FIG. 28B). The first configurationparameters may indicate a first RNTI (e.g., MBS-RNTI, SC-RNTI, G-RNTI,etc.) associated with the MBS session. The first configurationparameters may indicate a first PDSCH data scrambling identityassociated with the MBS session. The first configuration parameters mayindicate resource configuration parameters of a group common PDCCHassociated with the MBS session.

In an example embodiment, the second configuration parameters maycomprise configuration parameters of the BWP. The second configurationparameters may indicate a second RNTI (e.g., C-RNTI, CS-RNTI,MCS-C-RNTI, etc.) associated with the unicast transmissions dedicated tothe wireless device. The second configuration parameters may indicate asecond PDSCH data scrambling identity associated with the unicasttransmissions dedicated to the wireless device. The second configurationparameters may indicate resource configuration parameters of a unicastPDCCH associated with the unicast transmissions. In an example, thesecond RNTI may be different from the first RNTI. The second PDSCH datascrambling identity may be different from the first PDSCH datascrambling identity.

In an example embodiment, the wireless device may receive, based on thefirst RNTI and via the common frequency resources, a group common DCIscheduling a transport block of the MBS session. The group common DCImay be received with a first DCI format (e.g., DCI format 1_0/1_1/1_2 asdescribed above, or a new DCI format different from DCI format1_0/1_1/1_2 as described above). The wireless device may select, thefirst PDSCH data scrambling identity from the first PDSCH datascrambling identity and the second PDSCH data scrambling identity, basedon the group common DCI being received based on the first RNTI. In anexample, the wireless device may select the first PDSCH data scramblingidentity, regardless of whether the group common DCI is received withDCI format 1_0. The wireless device may receive (decode or detect), viathe common frequency resources, the transport block based on thetransport block being scrambled with a scrambling sequence, wherein thescrambling sequence is initialized by the selected first PDSCH datascrambling identity and the first RNTI.

In an example embodiment, the wireless device may receive, based on thesecond RNTI and via the BWP (e.g., outside of the common frequencyresources associated with the MBS session), a unicast DCI scheduling asecond transport block dedicated to the wireless device. The wirelessdevice may select, the second PDSCH data scrambling identity from thefirst PDSCH data scrambling identity and the second PDSCH datascrambling identity, based on the unicast DCI being received based onthe second RNTI. The wireless device may receive (decode or detect), viathe BWP (e.g., outside of the common frequency resources associated withthe MBS session), the second transport block based on the secondtransport block being scrambled with a second scrambling sequence,wherein the second scrambling sequence is initialized by the selectedsecond PDSCH data scrambling identity and the second RNTI. Exampleembodiment, based on determining a scrambling sequence being initializedby a data scrambling identity associated with an MBS session and a RNTIassociated with the MBS session, may increase robustness of multicasttransmission of an MBS session to a plurality of wireless devicesconfigured with the MBS session.

In an example embodiment, a scrambling sequence generator for thescrambling sequence may be initialized withc_(init)=n_(RNTI)·2¹⁵+q·2¹⁴+n_(ID), wherein n_(RNTI) corresponds to theMBS-RNTI associated with an MBS session. In an example, n_(ID) may beequal to zero. In an example, n_(ID) may be equal to a cell ID of thecell via which the wireless device receives MBS TBs of the MBS session.

In an example embodiment, when a base station determines a multicastretransmission of an MBS TB of an MBS session, the base station mayscramble the MBS TB with MBS-C-RNTI associated with the MBS session,wherein the MBS-C-RNTI may be configured dedicatedly for retransmissionof the MBS TB in a multicast transmission. In an example embodiment,when a base station determines a multicast retransmission of an MBS TBof an MBS session, the base station may scramble the MBS TB withMBS-RNTI associated with the MBS session, wherein the MBS-RNTI may beconfigured same for initial transmission and retransmission of the MBSTB.

FIG. 33 shows an example of HARQ process management for an MBS session,according to some embodiments (e.g., based on extension of exampleembodiments described above with respect to FIG. 32 ). A wireless devicemay receive from a base station one or more RRC messages comprisingconfiguration parameters of a cell. The configuration parameters mayindicate a plurality of HARQ processes (HARQ process x, HARQ process y,. . . , HARQ process m, HARQ process n, etc.) associated with the cell.The configuration parameters may indicate the plurality of HARQprocesses are grouped into HARQ process groups, each HARQ process groupcomprising one or more HARQ processes of the plurality of HARQprocesses. A first HARQ process group (e.g., comprising HARQ process m,HARQ process n, etc.) may be associated with unicast PDSCHtransmissions. One or more second HARQ process group (e.g., comprisingHARQ process x, HARQ process y, etc.) may be associated with MBStransmissions.

In an example embodiment, each MBS session of a plurality of MBSsessions may be associated with a respective HARQ process group of theone or more second HARQ process groups.

In an example, multiple MBS sessions of the plurality of MBS sessionsmay be associated with a shared HARQ process group of the one or moresecond HARQ process groups.

In an example embodiment, separating HARQ processes for unicasttransmissions and MBS transmissions may enable the base station or thewireless device to flexibly manage HARQ processes. Separating HARQprocesses for unicast transmissions and MBS transmissions may enable thewireless device to correctly decode a retransmitted MBS TB when theretransmitted MBS TB is scheduled by a unicast DCI and transmitted in aunicast PDSCH resource.

FIG. 32 and FIG. 33 may be combined. In an example embodiment, based onthe HARQ process grouping (e.g., as shown in FIG. 33 ), the wirelessdevice may determine whether a retransmission of an MBS TB is via amulticast transmission or via a unicast transmission (e.g., as shown inFIG. 32 ).

FIG. 34 shows an example of retransmission of an MBS TB in a unicastPDSCH resource, according to some embodiments (e.g., based on extensionof example embodiments described above with respect to FIG. 32 and/orFIG. 33 ). In an example embodiment, a wireless device may receive, froma base station, one or more RRC messages comprising configurationparameters of an MBS session. The one or more RRC messages may beimplemented based on the example embodiments described with respect toFIG. 32 .

In an example embodiment, the wireless device may receive a first DCI(1^(st) DCI in FIG. 34 ) with CRC scrambled by an MBS-RNTI via an MBSPDCCH in the BWP. The first DCI may be received in a first SS associatedwith the MBS session. The first DCI may be received in a first controlresource set associated with the MBS session. The first DCI may bereceived within the common frequency resources associated with the MBSsession. The first DCI may indicate downlink assignment of MBS PDSCHresources for initial transmission of an MBS TB (1^(st) TB in FIG. 34 ).The MBS TB, being scrambled by the MBS-RNTI, is transmitted to a groupof wireless devices configured with the MBS-RNTI. The first DCI maycomprise a HARQ process ID (PID=k in FIG. 34 ) indicating a HARQ processassociated with the MBS TB. The first DCI may comprise a first new dataindicator (NDI) value.

As shown in FIG. 34 , the wireless device may receive a multicastinitial transmission of the MBS TB via a first PDSCH resource indicatedby the first DCI. The wireless device may not successfully decode theMBS TB. Based on not successfully decoding the MBS TB, the wirelessdevice may buffer the received data for the MBS TB in a HARQ bufferassociated with a HARQ process (identified by the HARQ process ID).

In an example embodiment, the first DCI may be one of legacy DCI formats(e.g., DCI format 1_0/1_1/1_2), or a new DCI format different from thelegacy DCI formats. The first DCI may have less DCI payloads than thelegacy DCI format 1_0. In an example, the first DCI may comprise atleast one of: time domain resource assignment indication, VRB-to-PRBmapping indication, MCS indication, NDI, redundancy version, HARQprocess number, PUCCH resource indicator, PDSCH-to-HARQ_feedback timingindicator, ChannelAccess-CPext, etc. In an example embodiment, one ormore DCI fields (e.g., NDI, redundancy version, PUCCH resourceindicator, PDSCH-to-HARQ_feedback timing indicator, and/orChannelAccess-CPext, etc.) may be absent in the first DCI for MBS PDSCHscheduling.

As shown in FIG. 34 , the wireless device may transmit a HARQ NACKsignaling indicating that the wireless device did not successfullydecode the MBS TB. Based on the received HARQ NACK signaling, the basestation may determine a unicast retransmission of the MBS TB. The basestation may determine a unicast retransmission of the MBS TB based onthe example embodiments described with respect to FIG. 32 . The basestation may transmit a second DCI (2^(nd) DCI in FIG. 34 ) with CRCscrambled by C-RNTI via a unicast PDCCH in the BWP. The second DCI maybe received in a second search space which is a wireless device specificsearch space different from the first search space, wherein the firstsearch space is a common search space. The second DCI may be received inthe BWP (e.g., outside of the common frequency resources associated withthe MBS session). The second DCI may be received in a second controlresource set which is different from the first control resource setassociated with the MBS session. The second DCI may indicate downlinkassignment of unicast PDSCH resources for retransmission of the MBS TB.The retransmission of the MBS TB, being scrambled by the MBS-RNTI or bythe C-RNTI, is transmitted to the wireless device dedicatedly. Thesecond DCI may comprise a HARQ process ID (PID=k in FIG. 34 ) indicatinga same HARQ process as the initial transmission of the MBS TB.

As shown in FIG. 34 , the wireless device receives the second DCI. Thewireless device may receive data via a second PDSCH resource indicatedby the second DCI. In response to the HARQ ID of the second DCI beingsame as the HARQ ID of the first DCI and the second DCI being CRCscrambled by C-RNTI and the first DCI being CRC scrambled by MBS-RNTI,the wireless device may determine the received data in the second PDSCHresource is a retransmission of the MBS TB initially transmitted in thefirst PDSCH resource. Based on the HARQ ID of the second DCI being sameas the HARQ ID of the first DCI, the first DCI being received in asearch space different from the second DCI and the first DCI beingreceived in the common frequency resources where the second DCI isreceived outside of the common frequency resources, the wireless devicemay determine the received data in the second PDSCH resource is aretransmission of the MBS TB initially transmitted in the first PDSCHresource.

In an example embodiment, the wireless device may determine that an NDI,associated with a HARQ process identified by the HARQ ID, is not toggled(e.g., by comparing a second NDI of the second DCI and a first NDI ofthe first DCI). The wireless device may determine an NDI may be toggledor not toggled based on example embodiments described above with respectto FIG. 29 .

In an example, the wireless device may determine the NDI is not toggledregardless of an NDI value of the second DCI in response to the HARQ IDof the second DCI being the same as the HARQ ID of the first DCI and thesecond DCI being CRC scrambled by C-RNTI and the first DCI being CRCscrambled by MBS-RNTI. The wireless device may ignore the NDI value ofthe second DCI in response to the HARQ ID of the second DCI being thesame as the HARQ ID of the first DCI and the second DCI being CRCscrambled by C-RNTI and the first DCI being CRC scrambled by MBS-RNTI.

In an example, the wireless device, based on the NDI not being toggledand/or the HARQ ID of the second DCI being the same as the HARQ ID ofthe first DCI, may determine the received data in the second PDSCHresource is a retransmission of the MBS TB initially transmitted in thefirst PDSCH resource. Based on the NDI not being toggled and/or the HARQID of the second DCI being the same as the HARQ ID of the first DCI, thewireless device may combine the buffered data and the data received inthe second PDSCH resource for the MBS TB. The wireless device may decodethe combined data.

Based on the example shown in FIG. 32 , FIG. 33 and/or FIG. 34 , awireless device may determine a combination of a multicast initialtransmission of MBS TB with a unicast retransmission of the MBS TB,e.g., based on at least one of: a second NDI, of a unicast DCI receivedin a UE-specific search space and outside of the common frequencyresources of the BWP, being same as (or not being toggled compared with)a first NDI of a group common DCI received in a common search space andin common frequency resources within a BWP, a second HARQ process index,of the unicast DCI, being same as a first HARQ process index of thegroup common DCI. Example embodiment may improve system throughput whenHARQ is supported for an MBS session.

Example embodiments of FIG. 32 , FIG. 33 and/or FIG. 34 may be combined.In an example, a base station may configure (e.g., based on indicationof wireless device capability or without indication of the wirelessdevice capability) a retransmission type (or mode) for an MBS TB basedon example embodiments described above with respect to FIG. 32 . Thebase station, based on the retransmission type, may group a plurality ofHARQ processes into first HARQ processes associated with the MBS sessionand second HARQ processes associate with unicast transmissions, e.g.,based on example embodiments described above with respect to FIG. 33 .Based on the configured retransmission type and/or grouping theplurality of HARQ processes, the wireless device may determine receptionof a retransmission of an MBS TB based on example embodiments describedabove with respect to FIG. 34 . Example embodiments may improve powerconsumption of a wireless device, and/or system throughput of a basestation for MBS transmission.

FIG. 35 shows an example of retransmission of a TB when both a unicastretransmission of a unicast TB and a unicast retransmission of an MBS TBare supported, according to some embodiments.

As shown in FIG. 35 , a wireless device may receive a first DCI (1^(st)DCI) indicating a downlink assignment of a first PDSCH resource for afirst TB associated with a HARQ process (PID=k). The wireless device mayreceive the first data for the TB via the first PDSCH resource indicatedby the first DCI. The wireless device may store the HARQ information forthe HARQ process based on the example embodiments described with respectto FIG. 29 and/or FIG. 30 .

The wireless device may receive a second DCI (2^(nd) DCI) indicating adownlink assignment of a second PDSCH resource of a second TB associatedwith the same HARQ process (PID=k) as the first DCI. The wireless devicemay receive the second data for the second TB via the second PDSCHresource indicated by the second DCI. The second DCI may be with CRCscrambled by C-RNTI. The second DCI may comprise an NDI value.

As shown in FIG. 35 , the wireless device may determine a RNTI value forthe first DCI based on decoding the first DCI.

In response to the RNTI value of the first DCI being MBS-RNTI, the RNTIvalue of the second DCI being C-RNTI and the HARQ process ID of thesecond DCI being same as the first DCI, the wireless device maydetermine the unicast transmission scheduled by the second DCI is aretransmission of a multicast transmission of a MBS TB, based on exampleembodiments described above with respect to FIG. 34 . In an example,based on the RNTI value of the first DCI being MBS-RNTI, the RNTI valueof the second DCI being C-RNTI and the HARQ process ID of the second DCIbeing same as the first DCI, the wireless device may determine an NDIassociated with the HARQ Process k not being toggled (e.g., regardlessof the NDI value of the second DCI). Based on the NDI not being toggledand/or the HARQ process ID of the second DCI being same as the firstDCI, the wireless device may determine the second TB is the same as thefirst TB and the second data received in the second PDSCH resource is aretransmission of the first TB initially received in the first PDSCHresource. Based on the NDI not being toggled and/or the HARQ process IDof the second DCI being same as the first DCI, the wireless device maycombine the first data and the second data for the TB. The wirelessdevice may decode the combined data.

In response to the RNTI value of the first DCI being CS-RNTI (e.g., forsemi-persistent scheduling via periodic PDSCH resources for asemi-persistent scheduling configuration), the RNTI value of the secondDCI being C-RNTI and the HARQ process ID of the second DCI being thesame as the first DCI, the wireless device may determine an NDIassociated with the HARQ Process k being toggled regardless of the NDIvalue of the second DCI. Based on the NDI being toggled, the wirelessdevice may determine the second TB is different from the first TB andthe second data received in the second PDSCH resource is an initialtransmission of the second TB. Based on the NDI being toggled, thewireless device may decode the second TB based on the second data (andnot based on the first data).

Based on the example embodiment described with respect to FIG. 35 , thewireless device may manage HARQ retransmission for SPS and MBS. Exampleembodiment may improve system throughput when HARQ is supported for anMBS session.

FIG. 36 shows an example of retransmission of a TB when both unicastretransmissions of a unicast TB and an MBS TB are supported, accordingto some embodiments.

As shown in FIG. 36 , a wireless device may receive from a base stationone or more RRC messages comprising configuration parameters of a cell.The configuration parameters may indicate a plurality of HARQ processes(HARQ process x, HARQ process y, . . . , HARQ process m, HARQ process n,etc.) associated with the cell. The configuration parameters mayindicate the plurality of HARQ processes are grouped into HARQ processgroups, each HARQ process group comprising one or more HARQ processes ofthe plurality of HARQ processes. A first HARQ process group (e.g.,comprising HARQ process m, HARQ process n, etc.) may be associated withunicast PDSCH transmissions. One or more second HARQ process group(e.g., comprising HARQ process x, HARQ process y, etc.) may beassociated with MBS transmissions. The grouping of the plurality of HARQprocesses may be implemented based on the example embodiments describedwith respect to FIG. 33 .

As shown in FIG. 36 , the wireless device may receive a DCI indicating adownlink assignment of a first PDSCH resource for a first TB associatedwith a HARQ process (PID=k). The DCI, with CRC being scrambled byC-RNTI, may comprise a HARQ process ID indicating the HARQ process, anNDI value.

The wireless device may receive data for the TB via the first PDSCHresource indicated by the DCI. The wireless device may store the HARQinformation for the HARQ process and/or store the received data in aHARQ buffer of the HARQ process based on the example embodiments withrespect to FIG. 29 and/or FIG. 30 .

In an example embodiment, the wireless device may deactivate an activeBWP based on the example embodiments described with respect to FIG. 22 .The wireless device may flush HARQ buffers for the MBS in response todeactivating the active BWP. The wireless device may flush HARQ buffersfor the MBS when the MBS dedicated BWP is deactivated.

As shown in FIG. 36 , the wireless device may determine whether the HARQprocess belongs to the first HARQ process group or belongs to the ormore second HARQ process group.

In response to the HARQ process belonging to the first HARQ processgroup, the wireless device may determine the first TB is an initialtransmission or a retransmission of a unicast TB. The wireless devicemay determine the first TB is an initial transmission or aretransmission of a unicast TB based on an NDI value of the DCI, e.g.,by implementing the example embodiments described with respect to FIG.30 . In response to the HARQ process belonging to the first HARQ processgroup, the wireless device may determine whether the NDI is toggledbased on the NDI value of the DCI and a stored NDI value for a same HARQprocess. In response to the NDI being toggled, the wireless device maydetermine the data received in the first PDSCH resource is a new (orinitial) transmission of the first TB. The wireless device may decodethe received data for the first TB. In response to the NDI not beingtoggled, the wireless device may determine the data received in thefirst PDSCH resource is a retransmission of the first TB receivedpreviously. The wireless device may combine the data received in thefirst PDSCH resource and the data stored in the HARQ buffer previously.The wireless device may decode the combined data for the first TB.

In response to the HARQ process belonging to the one or more second HARQprocess group, the wireless device may determine the first TB is aunicast retransmission of an MBS TB. In response to the HARQ processbelonging to the one or more second HARQ process group, the wirelessdevice may determine the NDI is not toggled regardless of the NDI valueof the DCI. Based on the NDI not being toggled, the wireless device maycombine the received data in the first PDSCH and a buffered data for theMBS TB. The wireless device may decode the combined data for the MBS TB.

Example embodiments of FIG. 32 , FIG. 33 , FIG. 34 , FIG. 35 and/or FIG.36 may be combined as an embodiment. In an example, a base station mayconfigure (e.g., based on indication of wireless device capability orwithout indication of the wireless device capability) a retransmissiontype (or mode) for an MBS TB based on example embodiments describedabove with respect to FIG. 32 . The base station, based on theretransmission type, may group a plurality of HARQ processes into firstHARQ processes associated with the MBS session and second HARQ processesassociate with unicast transmissions, e.g., based on example embodimentsdescribed above with respect to FIG. 33 . Based on the configuredretransmission type and/or grouping the plurality of HARQ processes, thewireless device may determine reception of a retransmission of an MBS TBbased on example embodiments described above with respect to FIG. 34and/or FIG. 36 .

In an example, a wireless device may receive a group common DCIindicating a multicast transmission of first data of a TB, based onexample embodiments described above with respect to FIG. 34 . The groupcommon DCI may indicate a first HARQ process index. The first HARQprocess index may belong to first HARQ process indexes group of aplurality of HARQ process indexes groups, based on example embodimentsdescribed above with respect to FIG. 33 . The first HARQ process indexesgroup may be dedicatedly associated with the MBS transmissions. Thewireless device may determine the first data of the TB is associatedwith the multicast transmissions of an MBS session (which may bereferred to as a multicast TB in this specification) based on the firstHARQ process index belonging to the first HARQ process indexes group.The wireless device may determine the first data of the TB is associatedwith the multicast transmissions of an MBS session based on the firstHARQ process index not belonging to a HARQ process indexes groupassociated with unicast transmissions.

In an example, the wireless device may transmit a negative HARQ feedbackin response to a failure of decoding the multicast TB based on the firstdata, based on example embodiments described above with respect to FIG.34 .

In an example, the wireless device may receive a unicast DCI schedulinga unicast transmission of second data, based on example embodimentsdescribed above with respect to FIG. 34 . The unicast DCI may comprise asecond HARQ process index and a second NDI value. The wireless devicemay determine whether the unicast DCI schedules a unicast TB orschedules a retransmission of the multicast TB based on whether thesecond HARQ process index belongs to the first HARQ process indexesgroup or the second HARQ process indexes group, e.g., based on exampleembodiments described above with respect to FIG. 36 .

In an example, in response to the second HARQ process index, of theunicast DCI, belonging to the second HARQ process indexes groupassociated with the unicast transmissions, the wireless device maydetermine the second data is for a unicast TB. The wireless device maydecode the unicast TB based on the second data. The wireless device maynot combine the second data and the first data for decoding the unicastTB or for decoding the multicast TB.

In an example, in response to the second HARQ process index, of theunicast DCI, belonging to the first HARQ process indexes groupassociated with the MBS transmission, the wireless device may determinewhether the second data is for a retransmission of the multicast TBbased on at least one of: whether the second HARQ process index of theunicast DCI is same as the first HARQ process of the multicast DCI,whether a second NDI of the unicast DCI is same as a first NDI of themulticast DCI, e.g., based on example embodiments described above withrespect to FIG. 34 . In an example, the wireless device may determinethe second data is for a retransmission of the multicast TB based on atleast one of: the second HARQ process index of the unicast DCI beingsame as the first HARQ process of the multicast DCI, the second NDI ofthe unicast DCI being same as a first NDI of the multicast DCI. In anexample, the wireless device may determine the second data is for aninitial transmission of a second multicast TB based on at least one of:the second HARQ process index of the unicast DCI being different fromthe first HARQ process of the multicast DCI, the second NDI of theunicast DCI being different from a first NDI of the multicast DCI. Thesecond HARQ process index may belong to the first HARQ process indexesgroup associated with the MBS transmissions. The second HARQ processindex may not belong to the second HARQ process indexes group associatedwith the unicast transmissions. Example embodiments may improve powerconsumption of a wireless device, and/or system throughput of a basestation for MBS transmission.

In an example embodiment, a wireless device may receive, from a basestation and based on an MBS identifier, a first DCI indicating atransmission of an MBS TB of an MBS session. The wireless device, basedon the first DCI, may receive a first data of the MBS TB associated witha HARQ process. The wireless device may transmit negative feedback forthe MBS TB. The wireless device may receive a second data based on asecond DCI with a second identifier, the second DCI comprising an NDIvalue and a HARQ process identifier. The wireless device may determinean NDI of the HARQ process not being toggled regardless of the NDI valueof the second DCI in response to the HARQ process identifier indicatingthe HARQ process and CRC bits of the second DCI being scrambled by thesecond identifier. The wireless device may decode, based on the NDI notbeing toggled, the MBS TB based on a combination of the first data andthe second data.

In an example embodiment, the wireless device may receive, from the basestation, configuration parameters of a bandwidth part of a cell, whereinthe configuration parameters indicate the MBS identifier with the MBSsession and the second identifier associated with the wireless device.

In an example embodiment, the wireless device may transmit negativefeedback for the MBS TB and via an uplink control channel resource inresponse to decoding the MBS TB unsuccessful.

In an example embodiment, the second identifier may be a C-RNTIassociated with the wireless device. The MBS identifier may be anMBS-RNTI associated with the MBS session.

In an example embodiment, the wireless device may receive the first DCIin a first search space configured for the MBS session on a BWP of acell. The wireless device may receive the second DCI in a second searchspace configured for the wireless device to receive unicast PDCCH on aBWP of a cell.

In an example embodiment, the wireless device may monitor a PDCCH viathe second search space based on the second identifier. The wirelessdevice may store the first data in a HARQ buffer associated with theHARQ process.

In an example embodiment, the first data of the MBS TB may be scrambledby the MB S identifier. The second data of the MBS TB may be scrambledby the MBS identifier or the second identifier.

In an example embodiment, the MBS TB may be transmitted to a group ofwireless devices configured with the MBS session. The group of wirelessdevices may be configured with the MBS identifier based on the group ofwireless devices being subscribed to the MBS session.

In an example embodiment, the wireless device may be configured with theMBS identifier based on the wireless device being subscribed to the MBSsession. The wireless device may transmit, to the base station, an MBSinterest information indicating that the wireless device is interestedin the MBS session. The wireless device may receive an MBS commandindicating the base station starts the MBS session. The wireless devicemay monitor a PDCCH for the first DCI based on the MBS starting command.

In an example embodiment, the wireless device may skip transmitting apositive acknowledgement for the MBS TB in response to successfullydecoding the MBS TB based on the combination of the first data and thesecond data. The wireless device may transmit a positive acknowledgementfor the MBS TB in response to successfully decoding the MBS TB based onthe combination of the first data and the second data. In an exampleembodiment, the wireless device may transmit a negative acknowledgementfor the MBS TB in response to unsuccessfully decoding the MBS TB basedon the combination of the first data and the second data.

In an example, the wireless device may receive, from the base station, aretransmission type indication indicating that the MBS TB isretransmitted in a PDSCH resource dedicated to the wireless deviceand/or the retransmission of the MBS TB is scheduled by a unicast DCIaddressed to the wireless device. The retransmission type indication iscomprised in at least one of: one or more radio resource control messageand/or the first DCI.

In an example, a wireless device may receive, from a base station,configuration parameters indicating a plurality of HARQ processes beinggrouped into a first HARQ process group for unicast transmissions and asecond HARQ process group for MBS transmissions. The wireless device mayreceive, based on a C-RNTI, a DCI indicating a transmission of firstdata of a TB associated with a HARQ process. The wireless device mayreceive the first data for the TB associated with the HARQ process. Thewireless device may combine the first data and a buffered data for theTB in response to determining the HARQ process belonging to the secondHARQ process group. The wireless device may decode the TB based on thecombining the first data and the buffered data.

In an example, the DCI may comprise an NDI value and a HARQ processidentifier identifying the HARQ process. The wireless device maydetermine an NDI of the HARQ process not being toggled regardless of theNDI value of the DCI based on determining the HARQ process belonging tothe second HARQ process group and there being stored data in a HARQbuffer associated with the HARQ process. The wireless device maydetermine an NDI of the HARQ process not being toggled regardless of theNDI value of the DCI based on determining a second data of the TB isdecoded unsuccessfully, wherein the second data is scheduled by a secondDCI with MBS-RNTI, the second DCI indicating the HARQ process. Thewireless device may store the second data in a HARQ buffer of the HARQprocess. The buffered data may be the stored second data.

What is claimed is:
 1. A wireless device comprising: one or moreprocessors; and memory storing instructions that, when executed by theone or more processors, cause the wireless device to: receive, based ona radio network temporary identifier (RNTI) associated with a multicastand broadcast services (MBS) session, a group common downlink controlinformation (DCI) scheduling a transport block (TB) of the MBS session;based on the RNTI being associated with the MBS session, determine ascrambling identity for a TB of the MBS session; and receive the TBscrambled with a scrambling sequence initialized based on: a value ofthe scrambling identity; and a value of the RNTI.
 2. The wireless deviceof claim 1, wherein the instructions further cause the wireless deviceto receive one or more radio resource control (RRC) messages comprisingone or more configuration parameters for the MBS session, wherein theone or more configuration parameters comprise the RNTI associated withthe MBS session.
 3. The wireless device of claim 2, wherein: the one ormore configuration parameters further comprise a scrambling identityassociated with the MBS session; and the scrambling identity for the TBis the scrambling identifier associated with the MBS sessions.
 4. Thewireless device of claim 3, wherein the one or more configurationparameters further comprise a scrambling identity associated withunicast transmissions.
 5. The wireless device of claim 1, wherein: theinstructions further cause the wireless device to receive, via a cell,one or more radio resource control (RRC) messages comprising one or moreconfiguration parameters for the MBS session, wherein the one or moreconfiguration parameters comprise the RNTI associated with the MBSsession; and based on the one or more configuration parameters notcomprising a scrambling identity associated with the MBS session, thescrambling identity for the TB is a cell identifier (ID) of the cell. 6.The wireless device of claim 5, wherein the one or more configurationparameters further comprise a scrambling identity associated withunicast transmissions.
 7. The wireless device of claim 1, wherein: theinstructions further cause the wireless device to receive one or moreradio resource control (RRC) messages comprising one or moreconfiguration parameters for the MBS session, wherein the one or moreconfiguration parameters comprise: common frequency resources with abandwidth part (BWP) for the MBS session; and a scrambling identityassociated with the common frequency resources; and the scramblingidentity for the TB is the scrambling identifier associated with thecommon frequency resources.
 8. A base station comprising: one or moreprocessors; and memory storing instructions that, when executed by theone or more processors, cause the base station to: transmit, to awireless device based on a radio network temporary identifier (RNTI)associated with a multicast and broadcast services (MBS) session, agroup common downlink control information (DCI) scheduling a transportblock (TB) of the MBS session; based on the RNTI being associated withthe MBS session, determine a scrambling identity for a TB of the MBSsession; and transmit, to the wireless device, the TB scrambled with ascrambling sequence initialized based on: a value of the scramblingidentity; and a value of the RNTI.
 9. The base station of claim 8,wherein the instructions further cause the base station to transmit, tothe wireless device, one or more radio resource control (RRC) messagescomprising one or more configuration parameters for the MBS session,wherein the one or more configuration parameters comprise the RNTIassociated with the MBS session.
 10. The base station of claim 9,wherein: the one or more configuration parameters further comprise ascrambling identity associated with the MBS session; and the scramblingidentity for the TB is the scrambling identifier associated with the MBSsessions.
 11. The base station of claim 10, wherein the one or moreconfiguration parameters further comprise a scrambling identityassociated with unicast transmissions.
 12. The base station of claim 8,wherein the instructions further cause the base station to transmit, tothe wireless device via a cell, one or more radio resource control (RRC)messages comprising one or more configuration parameters for the MBSsession, wherein the one or more configuration parameters comprise theRNTI associated with the MBS session; and based on the one or moreconfiguration parameters not comprising a scrambling identity associatedwith the MBS session, the scrambling identity for the TB is a cellidentifier (ID) of the cell.
 13. The base station of claim 12, whereinthe one or more configuration parameters further comprise a scramblingidentity associated with unicast transmissions.
 14. The base station ofclaim 8, wherein: one or more radio resource control (RRC) messagescomprising one or more configuration parameters for the MBS session,wherein the one or more configuration parameters comprise: commonfrequency resources with a bandwidth part (BWP) for the MBS session; anda scrambling identity associated with the common frequency resources;and the scrambling identity for the TB is the scrambling identifierassociated with the common frequency resources.
 15. A non-transitorycomputer-readable medium comprising instructions that, when executed byone or more processors of a wireless device, cause the wireless deviceto: receive, based on a radio network temporary identifier (RNTI)associated with a multicast and broadcast services (MBS) session, agroup common downlink control information (DCI) scheduling a transportblock (TB) of the MBS session; based on the RNTI being associated withthe MBS session, determine a scrambling identity for a TB of the MBSsession; and receive the TB scrambled with a scrambling sequenceinitialized based on: a value of the scrambling identity; and a value ofthe RNTI.
 16. The non-transitory computer-readable medium of claim 15,wherein the instructions further cause the wireless device to receiveone or more radio resource control (RRC) messages comprising one or moreconfiguration parameters for the MBS session, wherein the one or moreconfiguration parameters comprise the RNTI associated with the MBSsession.
 17. The non-transitory computer-readable medium of claim 16,wherein: the one or more configuration parameters further comprise ascrambling identity associated with the MBS session; and the scramblingidentity for the TB is the scrambling identifier associated with the MBSsessions.
 18. The non-transitory computer-readable medium of claim 17,wherein the one or more configuration parameters further comprise ascrambling identity associated with unicast transmissions.
 19. Thenon-transitory computer-readable medium of claim 15, wherein: theinstructions further cause the wireless device to receive, via a cell,one or more radio resource control (RRC) messages comprising one or moreconfiguration parameters for the MBS session, wherein the one or moreconfiguration parameters comprise the RNTI associated with the MBSsession; and based on the one or more configuration parameters notcomprising a scrambling identity associated with the MBS session, thescrambling identity for the TB is a cell identifier (ID) of the cell.20. The non-transitory computer-readable medium of claim 15, wherein:the instructions further cause the wireless device to receive one ormore radio resource control (RRC) messages comprising one or moreconfiguration parameters for the MBS session, wherein the one or moreconfiguration parameters comprise: common frequency resources with abandwidth part (BWP) for the MBS session; and a scrambling identityassociated with the common frequency resources; and the scramblingidentity for the TB is the scrambling identifier associated with thecommon frequency resources.